{ "data": { "a": { "slug": "mailersend", "name": "MailerSend", "vendor": "MailerSend, Inc.", "vendorUrl": "https://www.mailersend.com", "kind": "http-api", "category": "email", "summary": "Transactional email service from MailerSend, Inc. with a REST API, SMTP relay, templates, inbound routing, webhooks and analytics, plus SMS and WhatsApp sending. Agents reach it with a scoped API token or through a hosted MCP server.", "url": "https://www.anchorterminal.com/tools/mailersend", "markdownUrl": "https://www.anchorterminal.com/tools/mailersend.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/mailersend.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/mailersend.json", "dns": "mailersend.grade.anchorterminal.com", "repo": "https://github.com/mailersend/mailersend-nodejs", "license": "Proprietary service under MailerSend's terms of use. The SDKs and the CLI on GitHub are MIT", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://api.mailersend.com/v1", "packages": [ { "registry": "npm", "name": "mailersend" }, { "registry": "pypi", "name": "mailersend" } ], "auth": "mixed", "authNotes": "The REST API takes a Bearer API token, created in the dashboard or through /v1/token, with any of 30 scopes and an optional sending domain. Tokens can be paused and deleted. SMTP relay uses separate SMTP users. The MCP server and the CLI use OAuth with a browser login, and the MCP authorisation server supports dynamic client registration and PKCE. Access is self-serve, but a new account passes an approval step before full sending.", "pricing": "freemium", "pricingNotes": "Free plan with 500 emails a month and 100 API requests a day, which the pricing FAQ says needs a card once the account is approved. A 14-day Professional trial starts at signup with the same limits. Hobby is $7 a month for 5,000 emails, Starter from $35 for 50,000 and Professional from $110 for 50,000, with overage of $0.50 to $1.50 per 1,000. Yearly billing takes 10 per cent off. Enterprise is priced by sales (https://www.mailersend.com/pricing, checked 2026-10-08).", "priceSummary": "$7 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the developer docs, the OpenAPI file or the pricing page (checked 2026-10-08).", "endpoints": [] }, "toolCount": 127, "popularity": { "githubStars": 175, "npmWeekly": 128453, "pypiWeekly": 15086, "asOf": "2026-10-08" }, "docsUrl": "https://developers.mailersend.com", "llmsTxt": "https://developers.mailersend.com/llms.txt", "openapi": "https://api.swaggerhub.com/apis/MailerSend/mailersend-api/1.0.0-oas3.1", "capabilities": [ "email.send", "email.inbound", "email.templates", "email.domains", "email.analytics", "email.verification", "email.threads", "messaging.sms", "messaging.whatsapp" ], "tags": [ "hosted", "freemium", "mcp", "oauth", "openapi", "llms-txt", "typescript", "python", "webhooks", "sms", "whatsapp", "status-page", "sla" ], "lastRelease": "2026-10-28", "graded": true, "anchor": { "graded": true, "score": 71.4, "grade": "BB", "agentReady": true, "rank": 161, "ranked": true, "rankOf": 1510, "categoryRank": 4, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 69, "maintenance": 85, "payments": 30, "reliability": 95, "schema": 80, "security": 63, "transparency": 68 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-01" }, "negative": 0, "verdict": "API tokens carry any of 30 scopes and can be tied to one domain, rate limits are published with retry-after on every 429, and a 99.5 per cent SLA starts on the $35 Starter plan. Sends take no idempotency key, the Free plan allows 100 API requests a day, and the terms permit changes without notice.", "bestFor": "An agent sending transactional email for an owner who wants scoped tokens, a hosted MCP server and low entry prices, with SMS and WhatsApp on the same API.", "strengths": [ "API tokens take any of 30 scopes, read or full by area, and can be limited to one sending domain", "Rate limits published per endpoint, with retry-after and x-ratelimit headers on a 429 and a quota endpoint that isn't counted", "99.5 per cent monthly uptime SLA with service credits on Starter, Professional and Enterprise", "Hosted MCP server at mcp.mailersend.com with OAuth, PKCE and dynamic client registration, on every plan", "Overage published per 1,000 emails for each plan, from $1.50 on Hobby to $0.50 at 2 million on Professional", "A Responsible Disclosure Program at security@mailersend.com with a discretionary bounty for severe bugs, and a DPA with a named sub-processor list" ], "weaknesses": [ "No idempotency key documented for POST /v1/email or the bulk endpoint", "Free plan is capped at 100 API requests a day and 500 emails a month, and asks for a card after account approval", "The terms allow MailerSend to change or end the service and the terms without notice, and to close an account without cause", "The MCP server lists 127 tools with no documented toolsets or read-only mode", "The public OpenAPI file has one-line summaries, no error responses, and no WhatsApp, DMARC or blocklist monitoring paths", "The terms grant MailerSend a licence to use inputs and outputs of its AI functions to improve AI models, and the DPA's sub-processor list omits OpenAI and Meta, which the privacy policy names" ], "agentNotes": [ "Send `Authorization: Bearer \u003ctoken\u003e` to https://api.mailersend.com/v1 and ask for a token with only the scopes the task needs, such as `email_full` and `activity_read`", "Read the message id from the `x-message-id` response header. POST /v1/email answers 202 with an empty body", "Check for a sent message before retrying a send. No idempotency key exists, so a blind retry can deliver twice", "On a 429 wait the seconds in `retry-after`. Call GET /v1/api-quota, which isn't counted, to see the daily quota left", "Use POST /v1/bulk-email for batches of up to 500 emails. It isn't on the Free plan and takes 10 to 60 requests a minute by plan" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 4, "avgRating": 2.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 71.4 } ], "editorialScores": { "ergonomics": 69, "maintenance": 85, "payments": 30, "reliability": 95, "schema": 80, "security": 63, "transparency": 49 }, "provenanceScore": 86, "checked": { "categories": { "ergonomics": "2026-11-01", "maintenance": "2026-11-01", "payments": "2026-11-01", "reliability": "2026-11-01", "schema": "2026-11-01", "security": "2026-11-01", "transparency": "2026-11-01" }, "last": "2026-11-01", "lastMoved": "2026-11-01", "oldest": "2026-11-01", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "npm install mailersend", "http": "curl -X POST https://api.mailersend.com/v1/email -H \"Authorization: Bearer $MAILERSEND_API_TOKEN\" \\\n -H \"Content-Type: application/json\" \\\n -d '{\"from\":{\"email\":\"hello@yourdomain.com\"},\"to\":[{\"email\":\"recipient@example.com\"}],\"subject\":\"Hello\",\"text\":\"Hello\"}'", "claudeCode": "claude mcp add --transport http mailersend https://mcp.mailersend.com/mcp" }, "letme": { "capability": "https://letme.dev/email.send", "tool": "https://letme.dev/mailersend" }, "area": "communication", "unitPrices": [ { "item": "Hobby", "unit": "month", "usd": 7, "note": "5,000 emails" }, { "item": "Starter 50k", "unit": "month", "usd": 35, "note": "50,000 emails" }, { "item": "Starter 100k", "unit": "month", "usd": 68, "note": "100,000 emails" }, { "item": "Professional 50k", "unit": "month", "usd": 110, "note": "50,000 emails" }, { "item": "Professional 100k", "unit": "month", "usd": 140, "note": "100,000 emails" }, { "item": "Overage on Hobby", "unit": "1k-emails", "usd": 1.5 }, { "item": "Overage on Starter", "unit": "1k-emails", "usd": 1.3, "note": "up to the 100,000 tier, $1.10 at 250,000 and 500,000, $1.00 at 1 million" }, { "item": "Overage on Professional", "unit": "1k-emails", "usd": 1.3, "note": "up to the 100,000 tier, falling to $0.50 at 2 million" }, { "item": "Email verification credit", "unit": "credit", "usd": 0.01, "note": "1,000 credits for $10, falling to $0.002 at 1 million" }, { "item": "Extra sending domain", "unit": "month", "usd": 4, "note": "per domain, Starter and above" }, { "item": "SMS phone number", "unit": "month", "usd": 2, "note": "per number, USA and Canada, Starter and above" } ], "provenance": { "legalEntity": "MailerSend, Inc.", "domain": "mailersend.com", "domainRegistered": "2009-11-12", "endpointOnVendorDomain": true, "terms": "https://www.mailersend.com/legal/terms-of-use", "privacy": "https://www.mailersend.com/legal/privacy-policy", "statusPage": "https://status.mailersend.com", "changelog": "https://www.mailersend.com/whats-new", "securityTxt": "none", "checked": "2026-11-01", "notes": [ "The terms of use (last updated 5 October 2026) and the privacy policy (last updated 15 October 2026) both name MailerSend, Inc., 228 Park Ave S, PMB 54955, New York, NY 10003-1502. The terms of use are the agreement for the service, with Delaware law.", "The API answers at api.mailersend.com and the MCP server at mcp.mailersend.com.", "www.mailersend.com/.well-known/security.txt returned 404 on 1 November. The legal index links a Responsible Disclosure Program (last updated 20 May 2024).", "The changelog at /whats-new was read on 1 November, with dated entries to 27 October 2026. On 8 October it answered with a Cloudflare bot check.", "RDAP gives 2009-11-12 as the registration date of mailersend.com.", "The lead named MailerLite and Vercom as parents. The DPA's sub-processor list names MailerLite Limited, MailerLite, Inc. and Vercom S.A. (\"as a shareholder\"), so Vercom is a shareholder on MailerSend's own page; no parent is recorded." ], "score": 86 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/mailersend.json", "live": { "slug": "mailersend", "probe": { "target": "https://api.mailersend.com/v1", "method": "get", "lastAt": "2026-11-07T19:22:17.789137569Z", "lastOk": true, "lastStatus": 200, "lastMs": 140, "authRequired": false, "uptime24h": 100, "uptime30d": 99.93, "p50ms24h": 157, "p95ms24h": 271, "samples24h": 238, "samples30d": 7450, "days": [ { "date": "2026-10-08", "probes": 70, "ok": 70 }, { "date": "2026-10-09", "probes": 250, "ok": 250 }, { "date": "2026-10-10", "probes": 247, "ok": 247 }, { "date": "2026-10-11", "probes": 247, "ok": 242 }, { "date": "2026-10-12", "probes": 247, "ok": 247 }, { "date": "2026-10-13", "probes": 248, "ok": 248 }, { "date": "2026-10-14", "probes": 249, "ok": 249 }, { "date": "2026-10-15", "probes": 253, "ok": 253 }, { "date": "2026-10-16", "probes": 252, "ok": 252 }, { "date": "2026-10-17", "probes": 253, "ok": 253 }, { "date": "2026-10-18", "probes": 256, "ok": 256 }, { "date": "2026-10-19", "probes": 255, "ok": 255 }, { "date": "2026-10-20", "probes": 252, "ok": 252 }, { "date": "2026-10-21", "probes": 253, "ok": 253 }, { "date": "2026-10-22", "probes": 253, "ok": 253 }, { "date": "2026-10-23", "probes": 248, "ok": 248 }, { "date": "2026-10-24", "probes": 251, "ok": 251 }, { "date": "2026-10-25", "probes": 250, "ok": 250 }, { "date": "2026-10-26", "probes": 252, "ok": 252 }, { "date": "2026-10-27", "probes": 249, "ok": 249 }, { "date": "2026-10-28", "probes": 251, "ok": 251 }, { "date": "2026-10-29", "probes": 248, "ok": 248 }, { "date": "2026-10-30", "probes": 249, "ok": 249 }, { "date": "2026-10-31", "probes": 251, "ok": 251 }, { "date": "2026-11-01", "probes": 249, "ok": 249 }, { "date": "2026-11-02", "probes": 250, "ok": 250 }, { "date": "2026-11-03", "probes": 248, "ok": 248 }, { "date": "2026-11-04", "probes": 246, "ok": 246 }, { "date": "2026-11-05", "probes": 185, "ok": 185 }, { "date": "2026-11-06", "probes": 241, "ok": 241 }, { "date": "2026-11-07", "probes": 197, "ok": 197 } ], "outages": [ { "start": "2026-10-11T07:15:12.490873409Z", "end": "2026-10-11T07:43:58.631045546Z", "note": "HTTP 503 server error" } ] }, "vendorStatus": { "page": "https://status.mailersend.com", "indicator": "none", "summary": "All Systems Operational", "checkedAt": "2026-11-07T19:22:26.834398607Z" }, "versions": [ { "registry": "github", "name": "mailersend/mailersend-nodejs", "version": "v3.7.0", "released": "2026-11-02", "seenAt": "2026-11-06T23:41:49.878789405Z" }, { "registry": "npm", "name": "mailersend", "version": "3.7.0", "seenAt": "2026-11-06T23:41:49.395248641Z" }, { "registry": "pypi", "name": "mailersend", "version": "2.2.0", "released": "2026-10-26", "seenAt": "2026-11-06T23:41:49.64928655Z" } ], "githubStars": 176, "npmWeekly": 115850, "pypiWeekly": 26821, "securityTxt": { "url": "https://mailersend.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:01:11.988959182Z" }, "llmsTxt": { "url": "https://developers.mailersend.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:56.111076066Z" }, "domain": { "domain": "mailersend.com", "registered": "2009-11-12", "source": "https://rdap.verisign.com/com/v1/domain/mailersend.com", "checkedAt": "2026-11-01T14:16:36.493893485Z" }, "pages": [ { "url": "https://www.mailersend.com/whats-new", "kind": "changelog", "status": 200, "checkedAt": "2026-11-07T14:31:13.086802822Z", "changedAt": "2026-11-03T08:08:04.115635581Z", "fingerprint": "4c3e11e80c08" }, { "url": "https://www.mailersend.com/pricing", "kind": "pricing", "status": 200, "checkedAt": "2026-11-07T14:31:11.132500464Z", "changedAt": "2026-10-29T05:24:44.621582322Z", "fingerprint": "6537fcab8ef4" }, { "url": "https://www.mailersend.com/legal/privacy-policy", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:31:06.858069156Z", "changedAt": "2026-10-15T22:11:18.251591995Z", "fingerprint": "22f596533c44" }, { "url": "https://www.mailersend.com/legal/terms-of-use", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:31:09.071749448Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "7fff1960a381" } ], "mcpTools": { "url": "https://mcp.mailersend.com/mcp", "checkedAt": "2026-11-07T01:46:06.835733304Z", "status": "auth", "note": "asks for credentials before listing its tools", "changedAt": "2026-11-07T01:46:06.835733304Z" }, "github": { "repo": "mailersend/mailersend-nodejs", "checkedAt": "2026-11-02T09:02:26.963738089Z", "stars": 176, "archived": false, "issuesEnabled": true, "pushedAt": "2026-10-29T09:43:33Z", "openIssues": 6, "openPRs": 3, "issuesOpened90d": 1, "issuesClosed90d": 0, "prsMerged90d": 15, "ci": { "branch": "main", "runs": 21, "success": 21, "failure": 0, "other": 0, "latest": "success", "latestAt": "2026-10-28T10:30:40Z" }, "replies": { "sampled": 25, "unanswered": 6, "medianDays": 67 } }, "updatedAt": "2026-11-07T19:22:17.789137569Z" } }, "answer": "MailerSend scores 71.4 (BB) on agent readiness against MailPace's 58.4 (C), and leads in 5 of 7 scored categories. MailPace leads on transparency \u0026 trust.", "b": { "slug": "mailpace", "name": "MailPace", "vendor": "OhMySMTP Ltd", "vendorUrl": "https://mailpace.com", "kind": "http-api", "category": "email", "summary": "MailPace is a UK transactional email service, formerly OhMySMTP, hosted in the EU. It sends mail through an HTTPS API or SMTP, turns inbound mail into webhooks and has a Domains and Email Status API.", "url": "https://www.anchorterminal.com/tools/mailpace", "markdownUrl": "https://www.anchorterminal.com/tools/mailpace.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/mailpace.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/mailpace.json", "dns": "mailpace.grade.anchorterminal.com", "repo": "https://github.com/mailpace/mailpace-mcp", "transports": [ "http" ], "packages": [ { "registry": "npm", "name": "@mailpace/mailpace.js" } ], "auth": "api-key", "authNotes": "Each domain has its own server token, sent in the `MailPace-Server-Token` header, which can send from that domain and read its email status. An organisation token in `MailPace-Organization-Token` manages domains and domain tokens through the Domains API, including revoking them. Both are made in the dashboard after a browser signup.", "pricing": "paid", "pricingNotes": "$10 a month includes 10,000 emails sent or received, then $1 per 1,000, per the Paddle prices the pricing page loads and the comparison pages ($100 for 100,000, $1,000 for 1 million). A free plan of up to 100 emails a month is given on request by email. Paddle is the merchant of record; card, PayPal, Apple Pay or Google Pay.", "priceSummary": "$10 / mo", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the docs repository, the pricing page or the MCP server source (checked 2026-11-06). Payment is by Paddle subscription; the FAQ says crypto isn't accepted.", "endpoints": [] }, "toolCount": 12, "popularity": { "githubStars": 1, "npmWeekly": 207, "pypiWeekly": null, "asOf": "2026-11-06" }, "docsUrl": "https://docs.mailpace.com/", "capabilities": [ "email.send", "email.inbound", "email.domains", "email.analytics" ], "tags": [ "hosted", "closed-source", "smtp", "webhooks", "idempotency", "status-page", "sla", "eu", "mcp", "typescript", "ruby", "go", "php" ], "lastRelease": "2026-10-22", "graded": true, "anchor": { "graded": true, "score": 58.4, "grade": "C", "agentReady": false, "rank": 754, "ranked": true, "rankOf": 1510, "categoryRank": 17, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 71, "maintenance": 65, "payments": 25, "reliability": 70, "schema": 54, "security": 50, "transparency": 75 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-06" }, "negative": 0, "verdict": "A small transactional sender with idempotent sends, signed webhooks, a 99% availability promise in its terms and a public Upptime status record. There is no OpenAPI spec, no published rate limit, no llms.txt, and its MCP server was rewritten on 4 November 2026 but isn't on npm or in the MCP registry yet.", "bestFor": "Low-volume transactional mail from EU-hosted infrastructure with idempotent sends and no tracking.", "strengths": [ "Sends accept an `Idempotency-Key` header kept for 24 hours, so a retry after a timeout doesn't send twice", "Per-domain server tokens limit a leaked key to one domain, and organisation tokens can create and revoke them by API", "Webhooks are signed with Ed25519 and inbound mail is retried five times before it fails", "Status page on Upptime with GitHub issues as incident reports, and a 99% monthly availability promise with credits in the terms", "Sub-processors and their locations are listed, and mail is kept 30 days plus 7 in backups per the DPA" ], "weaknesses": [ "No OpenAPI spec, llms.txt or Markdown docs for agents; the reference is Docusaurus pages", "Rate limits aren't published; the docs say they vary by organisation age, plan and history", "No free plan without emailing support, and the paid plan starts at $10 a month", "MCP server 2.0.0 exists only in the repository; npm and the MCP registry had nothing for it on 6 November 2026", "No security.txt, disclosure policy or certification found" ], "agentNotes": [ "Send a UUID in `Idempotency-Key` on every `POST /api/v1/send`, and reuse it on a retry; keys last 24 hours and are tied to one token", "Use the server token of the sending domain, since the From domain must match the token's domain or the API returns 403", "On 429 `You are sending emails too quickly` back off; no Retry-After is documented", "Send only transactional mail; marketing and bulk newsletters are prohibited by the docs and terms", "Read delivery with `GET /api/v1/domains/:domain_id/emails/:id` using the id the send returned" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 58.4 } ], "editorialScores": { "ergonomics": 71, "maintenance": 65, "payments": 25, "reliability": 70, "schema": 54, "security": 50, "transparency": 69 }, "provenanceScore": 81, "checked": { "categories": { "ergonomics": "2026-11-06", "maintenance": "2026-11-06", "payments": "2026-11-06", "reliability": "2026-11-06", "schema": "2026-11-06", "security": "2026-11-06", "transparency": "2026-11-06" }, "last": "2026-11-06", "oldest": "2026-11-06", "stale": false, "staleAfterDays": 90 } }, "connect": { "http": "curl https://app.mailpace.com/api/v1/send -X POST -H \"Accept: application/json\" -H \"Content-Type: application/json\" -H \"MailPace-Server-Token: $MAILPACE_TOKEN\" -H \"Idempotency-Key: $(uuidgen)\" -d '{\"from\":\"you@yourdomain.com\",\"to\":\"person@example.com\",\"subject\":\"Hello\",\"textbody\":\"Hello\"}'" }, "letme": { "capability": "https://letme.dev/email.send", "tool": "https://letme.dev/mailpace" }, "area": "communication", "unitPrices": [ { "item": "Scaling plan", "unit": "month", "usd": 10, "note": "includes 10,000 emails sent or received" }, { "item": "Emails beyond 10,000", "unit": "1k-emails", "usd": 1 } ], "provenance": { "legalEntity": "OhMySMTP Ltd", "domain": "mailpace.com", "domainRegistered": "2022-01-10", "endpointOnVendorDomain": true, "terms": "https://mailpace.com/terms", "privacy": "https://mailpace.com/privacy", "statusPage": "https://status.mailpace.com", "changelog": "https://mailpace.com/category/changelog", "securityTxt": "none", "checked": "2026-11-06", "notes": [ "The terms and privacy policy name OhMySMTP Ltd, incorporated in England and Wales, company number 13200428. Companies House lists two active directors.", "Terms last updated 9 January 2026, privacy policy 30 August 2026, DPA updated in October 2026 per the landing repository.", "mailpace.com/robots.txt allows all paths. The terms contain no clause on automated access to the website beyond the usual licence limits.", "RDAP gives mailpace.com a registration date of 10 January 2022; the service ran as OhMySMTP before that.", "/.well-known/security.txt returns 404 on mailpace.com and app.mailpace.com." ], "score": 81 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/mailpace.json", "live": { "slug": "mailpace", "vendorStatus": { "page": "https://status.mailpace.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:48:01.553362214Z" }, "versions": [ { "registry": "npm", "name": "@mailpace/mailpace.js", "version": "0.1.3", "seenAt": "2026-11-06T23:42:02.752996422Z" } ], "githubStars": 1, "npmWeekly": 207, "securityTxt": { "url": "https://mailpace.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:01:07.630537329Z" }, "pages": [ { "url": "https://mailpace.com/category/changelog", "kind": "changelog", "status": 200, "checkedAt": "2026-11-07T14:13:40.841899008Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "38f92a159d1b" }, { "url": "https://mailpace.com/privacy", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:13:45.28058492Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "e6b0fea49c1d" }, { "url": "https://mailpace.com/terms", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:13:45.480605157Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "24f1eed01dad" } ], "updatedAt": "2026-11-07T16:01:07.630537329Z" } }, "edges": [ { "by": 26, "category": "schema", "leads": "mailersend", "name": "Schema \u0026 documentation", "reasons": { "a": "OpenAPI 3.1 on SwaggerHub with 59 paths and 97 operations, but no WhatsApp, DMARC or blocklist monitoring paths and no error responses, per the 8 October check (20 of 25). llms.txt on the docs site, now indexing the WhatsApp messages, items, activities, inbound, recipients, templates and webhooks pages, and every page served as Markdown at \u003cpath\u003e.md (10). The OpenAPI file has one-line summaries only, while the reference pages state limits and plan conditions per endpoint. The MCP tool definitions can't be read without an account (10 of 20). Parameter tables give type, required and limits, such as 50 To recipients and the nine template languages. The spec has 6 enums (11 of 15). Request examples in up to seven languages and 52 MS error codes with explanations (14). /v1 in the path and a dated public changelog at /whats-new, read on 1 November after a bot check on 8 October, with eight entries between 4 August and 27 October 2026 (15).", "b": "No OpenAPI or other machine-readable contract for the HTTPS API. The MCP server's 12 tools have typed zod inputs and output schemas, but that server isn't published yet, so partial credit (8 of 25). llms.txt answers 404 on mailpace.com and docs.mailpace.com, and no Markdown copies are served (0). The reference states what each endpoint does, and the introduction says when not to use it (transactional only, no batch, no static IPs) (12 of 20). Field tables give type, examples and required or optional, with enums for status, sort and direction and the 50-recipient cap in text (9 of 15). Examples in curl and six languages and a full table of error responses with messages, though several listed messages have a broken quote (`{\"error:\"...`) and the send reference says 30 MB where the home page says 25 MB (12 of 15). Version in the path with a promise that an old version runs until a published end-of-life date, and dated changelog posts (13 of 15). Total 54." }, "scores": { "a": 80, "b": 54 } }, { "by": 25, "category": "reliability", "leads": "mailersend", "name": "Reliability", "reasons": { "a": "Graded on the hosted REST API. Status page at status.mailersend.com (incident.io) with ten components and per-component uptime (20). The status feed, re-read on 1 November, lists two completed maintenance windows inside 90 days (a five-minute sending maintenance on 21 September and database maintenance on 11 October) and no incident (30). Rate limits published per endpoint, 120 requests a minute on POST /v1/email, with daily quotas by plan (15). A 429 carries retry-after, x-ratelimit and x-apiquota headers, and the docs say to wait the stated seconds. No idempotency key for sends (10 of 15). A 99.5 per cent monthly uptime SLA with service credits from Starter (10). GA (10).", "b": "Graded with the hosted lines. A public Upptime status page at status.mailpace.com, driven by the mailpace/status repository, with monitors for the application, SMTP, docs, blog and landing page and GitHub issues as incident reports (20). The 90 days from 8 August hold two incidents, an application outage on 22 September 2026 that the operator put down to an upstream provider returning 5xx (issue open for two minutes), and SMTP down on 2 November 2026 for about 35 minutes, which leaves SMTP at 99.65% for the week. Minor incidents only (20). No rate limit numbers are published; the docs say limits vary by organisation age, plan and history (0). A documented 429 with its message, no Retry-After or backoff guidance, and an `Idempotency-Key` on sends with written retry rules (10 of 15). The terms guarantee 99% monthly availability of the API and dashboard with a 5% credit per 30 minutes (10). The API is at v1 with no beta label (10). Total 70." }, "scores": { "a": 95, "b": 70 } }, { "by": 20, "category": "maintenance", "leads": "mailersend", "name": "Maintenance \u0026 community", "reasons": { "a": "Node.js SDK v3.7.0 on 28 October 2026 and the changelog's isolated domain reputation entry on 27 October (30). In the last 90 days the Node.js SDK tagged seven releases (10 August to 28 October), the Python SDK four (1 September to 26 October) and the CLI one, and the changelog has eight dated entries (20). The SDK repositories merge pull requests weekly and the CLI took two in October. We couldn't read issue replies (GitHub refuses our reader), and the product changelog is public and dated, with a help centre and support team we didn't test (12 of 15). Current official SDKs in seven languages, Node.js, Python, PHP, Go, Java, Ruby and the Laravel driver, all but the Laravel driver tagged in October (15). Renovate and a test matrix on Node 20, 22 and 24 in the Node.js SDK. The Python SDK has tests but only a publish workflow, and on 8 October npm's latest was 3.4.1 while the repository had tagged 3.5.0 on 23 September, not re-read on 1 November (8 of 10). 30 + 20 + 12 + 15 + 8 = 85.", "b": "Email Status API documented on 22 October 2026, and the MCP server rewritten as 2.0.0 on 4 November 2026, two days before this check (30). In the 90 days from 8 August, the Q3 changelog post of 31 August, the Email Status docs of 22 October, a mailpace-rails push on 17 October and the MCP rewrite, but only one changelog post (15 of 20). A closed service with email support. Three pull requests to the MCP repository from 2025 have no reply (8 of 15). Not in the official MCP registry (search for mailpace returned nothing on 6 November). The Node library was last pushed in October 2024 and Go in January 2024, while mailpace-rails is current (7 of 15). The MCP server gained CI with tests on 4 November; the older SDKs weren't checked for CI (5 of 10). Total 65." }, "scores": { "a": 85, "b": 65 } }, { "by": 13, "category": "security", "leads": "mailersend", "name": "Security \u0026 auth", "reasons": { "a": "API tokens with any of 30 scopes, read or full by area, optionally tied to one sending domain, and pausable or deletable through the API. OAuth with PKCE and dynamic client registration on the MCP server and the CLI (30). Read scopes, token pause and IP allowlisting from Starter. No confirmation step documented for deletes or sends (13 of 20). Inbound mail and activity data carry untrusted content. The terms place responsibility for a connected agent on the customer, and no injection guidance was found in the docs (3 of 15). Email activity logs on every plan for 1 to 30 days, API request logs only on Professional (7 days) and Enterprise (14 days) (9 of 15). The Responsible Disclosure Program (last updated 20 May 2024), read on 1 November after a bot check on 8 October, takes reports at security@mailersend.com and pays a bounty, at MailerSend's discretion, for severe bugs. No security.txt and no public advisories. The security statement cites ISO 27001 for Google's data centre and names no SOC 2 or ISO 27001 of MailerSend's own. A guide covers leaked credentials. That's a disclosure route with rewards paid at MailerSend's discretion and no certification of its own, the same as contactsplus (8, a disclosure policy and discretionary bounties, no SOC 2 or ISO 27001), below ahasend and brevo (12 each, ISO 27001 and a disclosure route) and above postmark (5, neither) (8 of 20). 30 + 13 + 3 + 9 + 8 = 63.", "b": "Per-domain server tokens that can only send from and read status for their domain, and an organisation token that creates, renames and revokes domain tokens through the Domains API. Tokens travel in headers only. The authentication page still tells users to contact support to regenerate a leaked token (25 of 30). No read-only token. A domain token can't touch other domains, and the unpublished MCP server has an optional recipient allowlist. No approval step on the hosted API (8 of 20). Inbound mail reaches the customer's webhook as untrusted content, and Email Status returns bounce text. The MCP README warns about prompt injection and suggests the allowlist (9 of 15). The dashboard keeps sent mail for 30 days; no log of API calls was found (6 of 15). No security.txt (404 on mailpace.com and app.mailpace.com), no disclosure policy, bug bounty, SOC 2 or ISO 27001. WebAuthn-only two-factor sign-in and Ed25519-signed webhooks are documented (2 of 20). Total 50." }, "scores": { "a": 63, "b": 50 } }, { "by": 7, "category": "transparency", "leads": "mailpace", "name": "Transparency \u0026 trust", "reasons": { "a": "Closed service with published terms (last updated 5 October 2026) and MIT SDKs. The terms allow changes to the service and the terms without notice and account closure without cause (17 of 30). The privacy policy (last updated 15 October 2026) gives deletion within 30 days of a request, removal of accounts inactive for two years, and EU data centres, and the Data Processing Addendum (last updated 31 August 2026), read on 1 November, adds deletion on request after termination and standard contractual clauses. Activity retention by plan is on the pricing page. The terms grant a licence to use the inputs and outputs of AI functions to improve AI models, and the two documents don't name the same processors (below), so the line holds (18 of 30). No deprecation policy found in the docs, and the terms reserve change without notice (0). The DPA's Annex 4 lists five sub-processors with addresses (Google Cloud EMEA with a data centre in Belgium, MailerLite Limited, MailerLite, Inc., Vercom S.A. and Bandwidth) and promises 10 days' notice of changes, but the privacy policy also names OpenAI and Meta, which the list leaves out (14 of 20). 17 + 18 + 0 + 14 = 49.", "b": "Closed hosted service under terms that name OhMySMTP Ltd with its company number. The MCP server, SDKs, landing site and status page are MIT (18 of 30). The privacy policy (30 August 2026), the pricing page and the DPA agree on retention, 30 days in the dashboard and 7 more in backups, 37 days at most (25 of 30). The API reference promises an old version runs until a published end-of-life date, and the terms list dated changes. The terms also say changes apply immediately (8 of 20). Sub-processors listed with purpose and location, Freethought hosting in the EU, Hetzner backups in Germany, AppSignal in Amsterdam, Paddle in the UK and Tutanota in Germany (18 of 20). Total 69." }, "scores": { "a": 68, "b": 75 } }, { "by": 5, "category": "payments", "leads": "mailersend", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 (0). Plan prices and overage per 1,000 emails are public for every plan, $1.50 on Hobby and $1.30 on Starter at 50,000, per the 8 October check; on 1 November the page's figures render by script and the FAQ still gives $1.30 per 1,000 on Starter (20). The 14-day trial starts at signup with 500 emails and 100 API requests a day, but the pricing FAQ says the Free plan asks for card details \"to prevent abuse\". Whether the trial needs a card wasn't established, so half (10 of 20). Browser signup and an account approval step before full sending (0).", "b": "No x402, MPP or L402 (0). $10 a month for 10,000 emails and $1 per 1,000 after, loaded from Paddle on the pricing page and stated in the comparison pages' tables without login (20). A free plan of up to 100 emails a month is available only by emailing support, so it isn't self-serve (5 of 20). Signup, DKIM verification and payment happen in a browser (0). Total 25." }, "scores": { "a": 30, "b": 25 } } ], "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "MailerSend, Inc.", "b": "OhMySMTP Ltd", "name": "Vendor" }, { "a": "https://api.mailersend.com/v1", "b": "no (local only)", "name": "Hosted endpoint" }, { "a": "HTTP, Streamable HTTP", "b": "HTTP", "name": "Transports" }, { "a": "OAuth or key", "b": "API key", "name": "Auth" }, { "a": "Freemium", "b": "Paid", "name": "Pricing" }, { "a": "$4 per month (plan)", "b": "not published", "name": "Price for sending email" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Proprietary service under MailerSend's terms of use. The SDKs and the CLI on GitHub are MIT", "b": "none", "name": "Licence" }, { "a": "127", "b": "12", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "no", "name": "llms.txt" }, { "a": "2026-10-28", "b": "2026-10-22", "name": "Last release" }, { "a": "2026-10-05", "b": "2026-01-09", "name": "Terms last updated" }, { "a": "2026-09-17", "b": "2026-08-30", "name": "Privacy policy last updated" }, { "a": "yes", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "not found in the text", "b": "yes", "name": "Terms restrict automated access" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "yes", "b": "not found in the text", "name": "Terms or service can change without notice" }, { "a": "yes", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "175 stars, 128k npm/wk, 15k PyPI/wk", "b": "1 stars, 207 npm/wk", "name": "Popularity" }, { "a": "2.5/5 (4)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "MailerSend scores 71.4 (BB) on agent readiness against MailPace's 58.4 (C), and leads in 5 of 7 scored categories. MailPace leads on transparency \u0026 trust.", "question": "Which is better for AI agents, MailerSend or MailPace?" }, { "answer": "MailerSend takes an API key or an OAuth sign-in. MailPace needs an API key.", "question": "Do MailerSend and MailPace need an API key?" }, { "answer": "MailerSend has a hosted endpoint at https://api.mailersend.com/v1. No hosted endpoint is listed for MailPace.", "question": "Can an agent call MailerSend and MailPace without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 95 against 70", "Schema \u0026 documentation, 80 against 54", "Security \u0026 auth, 63 against 50", "Payments \u0026 pricing, 30 against 25", "Maintenance \u0026 community, 85 against 65" ], "also": [ "Agent-ready, a grade of BB or better", "A hosted endpoint, with nothing to install" ], "goodFor": "An agent sending transactional email for an owner who wants scoped tokens, a hosted MCP server and low entry prices, with SMS and WhatsApp on the same API.", "slug": "mailersend", "watchFor": "No idempotency key documented for POST /v1/email or the bulk endpoint" }, { "aheadOn": [ "Transparency \u0026 trust, 75 against 68" ], "also": null, "goodFor": "Low-volume transactional mail from EU-hosted infrastructure with idempotent sends and no tracking.", "slug": "mailpace", "watchFor": "No OpenAPI spec, llms.txt or Markdown docs for agents; the reference is Docusaurus pages" } ], "history": { "mailersend": [ { "causes": [ "evidence" ], "date": "2026-11-01", "delta": 1.8, "from": 69.6, "fromGrade": "B", "to": 71.4, "toGrade": "BB" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.1, "from": 69.5, "fromGrade": "B", "to": 69.6, "toGrade": "B" } ], "mailpace": null }, "job": { "capability": "email.send", "name": "Sending email" }, "others": [ { "json": "https://www.anchorterminal.com/compare/ahasend-vs-mailersend.json", "title": "AhaSend API + MCP vs MailerSend", "url": "https://www.anchorterminal.com/compare/ahasend-vs-mailersend" }, { "json": "https://www.anchorterminal.com/compare/ahasend-vs-mailpace.json", "title": "AhaSend API + MCP vs MailPace", "url": "https://www.anchorterminal.com/compare/ahasend-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/amazon-ses-vs-mailersend.json", "title": "Amazon SES vs MailerSend", "url": "https://www.anchorterminal.com/compare/amazon-ses-vs-mailersend" }, { "json": "https://www.anchorterminal.com/compare/amazon-ses-vs-mailpace.json", "title": "Amazon SES vs MailPace", "url": "https://www.anchorterminal.com/compare/amazon-ses-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/brevo-vs-mailersend.json", "title": "Brevo API + MCP vs MailerSend", "url": "https://www.anchorterminal.com/compare/brevo-vs-mailersend" }, { "json": "https://www.anchorterminal.com/compare/brevo-vs-mailpace.json", "title": "Brevo API + MCP vs MailPace", "url": "https://www.anchorterminal.com/compare/brevo-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.json", "title": "Cloudflare Email Service vs MailerSend", "url": "https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend" }, { "json": "https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailpace.json", "title": "Cloudflare Email Service vs MailPace", "url": "https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/groundmail-vs-mailersend.json", "title": "Groundmail API + MCP vs MailerSend", "url": "https://www.anchorterminal.com/compare/groundmail-vs-mailersend" }, { "json": "https://www.anchorterminal.com/compare/groundmail-vs-mailpace.json", "title": "Groundmail API + MCP vs MailPace", "url": "https://www.anchorterminal.com/compare/groundmail-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/loops-vs-mailersend.json", "title": "Loops API + MCP vs MailerSend", "url": "https://www.anchorterminal.com/compare/loops-vs-mailersend" }, { "json": "https://www.anchorterminal.com/compare/loops-vs-mailpace.json", "title": "Loops API + MCP vs MailPace", "url": "https://www.anchorterminal.com/compare/loops-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-mailgun.json", "title": "MailerSend vs Mailgun API + MCP", "url": "https://www.anchorterminal.com/compare/mailersend-vs-mailgun" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-mailjet.json", "title": "MailerSend vs Mailjet API + MCP", "url": "https://www.anchorterminal.com/compare/mailersend-vs-mailjet" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-mailtrap.json", "title": "MailerSend vs Mailtrap Email API + MCP", "url": "https://www.anchorterminal.com/compare/mailersend-vs-mailtrap" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-mandrill.json", "title": "MailerSend vs Mailchimp Transactional (Mandrill)", "url": "https://www.anchorterminal.com/compare/mailersend-vs-mandrill" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-postmark.json", "title": "MailerSend vs Postmark API + MCP", "url": "https://www.anchorterminal.com/compare/mailersend-vs-postmark" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-resend.json", "title": "MailerSend vs Resend API + MCP", "url": "https://www.anchorterminal.com/compare/mailersend-vs-resend" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-sendgrid.json", "title": "MailerSend vs Twilio SendGrid", "url": "https://www.anchorterminal.com/compare/mailersend-vs-sendgrid" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-sendlayer.json", "title": "MailerSend vs SendLayer", "url": "https://www.anchorterminal.com/compare/mailersend-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-smtp2go.json", "title": "MailerSend vs SMTP2GO API + MCP", "url": "https://www.anchorterminal.com/compare/mailersend-vs-smtp2go" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-zoho-zeptomail.json", "title": "MailerSend vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/mailersend-vs-zoho-zeptomail" }, { "json": "https://www.anchorterminal.com/compare/mailgun-vs-mailpace.json", "title": "Mailgun API + MCP vs MailPace", "url": "https://www.anchorterminal.com/compare/mailgun-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/mailjet-vs-mailpace.json", "title": "Mailjet API + MCP vs MailPace", "url": "https://www.anchorterminal.com/compare/mailjet-vs-mailpace" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-mailtrap.json", "title": "MailPace vs Mailtrap Email API + MCP", "url": "https://www.anchorterminal.com/compare/mailpace-vs-mailtrap" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-mandrill.json", "title": "MailPace vs Mailchimp Transactional (Mandrill)", "url": "https://www.anchorterminal.com/compare/mailpace-vs-mandrill" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-postmark.json", "title": "MailPace vs Postmark API + MCP", "url": "https://www.anchorterminal.com/compare/mailpace-vs-postmark" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-resend.json", "title": "MailPace vs Resend API + MCP", "url": "https://www.anchorterminal.com/compare/mailpace-vs-resend" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-sendgrid.json", "title": "MailPace vs Twilio SendGrid", "url": "https://www.anchorterminal.com/compare/mailpace-vs-sendgrid" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-sendlayer.json", "title": "MailPace vs SendLayer", "url": "https://www.anchorterminal.com/compare/mailpace-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-smtp2go.json", "title": "MailPace vs SMTP2GO API + MCP", "url": "https://www.anchorterminal.com/compare/mailpace-vs-smtp2go" }, { "json": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.json", "title": "MailPace vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail" } ], "panel": null, "scores": [ { "by": 25, "edge": "mailersend", "key": "reliability", "mailersend": 95, "mailpace": 70, "name": "Reliability", "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 26, "edge": "mailersend", "key": "schema", "mailersend": 80, "mailpace": 54, "name": "Schema \u0026 documentation", "weight": 13 }, { "by": 2, "edge": "mailpace", "key": "ergonomics", "mailersend": 69, "mailpace": 71, "name": "Agent ergonomics", "weight": 13 }, { "by": 13, "edge": "mailersend", "key": "security", "mailersend": 63, "mailpace": 50, "name": "Security \u0026 auth", "weight": 14 }, { "by": 5, "edge": "mailersend", "key": "payments", "mailersend": 30, "mailpace": 25, "name": "Payments \u0026 pricing", "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 20, "edge": "mailersend", "key": "maintenance", "mailersend": 85, "mailpace": 65, "name": "Maintenance \u0026 community", "weight": 7 }, { "by": 7, "edge": "mailpace", "key": "transparency", "mailersend": 68, "mailpace": 75, "name": "Transparency \u0026 trust", "weight": 7 } ], "summary": "MailerSend scores 71.4 (BB) on agent readiness against MailPace's 58.4 (C), and leads in 5 of 7 scored categories. MailPace leads on transparency \u0026 trust. Both do sending email.", "tasks": null, "tutorials": [], "verdicts": { "mailersend": "API tokens carry any of 30 scopes and can be tied to one domain, rate limits are published with retry-after on every 429, and a 99.5 per cent SLA starts on the $35 Starter plan. Sends take no idempotency key, the Free plan allows 100 API requests a day, and the terms permit changes without notice.", "mailpace": "A small transactional sender with idempotent sends, signed webhooks, a 99% availability promise in its terms and a public Upptime status record. There is no OpenAPI spec, no published rate limit, no llms.txt, and its MCP server was rewritten on 4 November 2026 but isn't on npm or in the MCP registry yet." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace", "json": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace.min.md" }, "markdown": "MailerSend scores 71.4 (BB) on agent readiness against MailPace's 58.4 (C), and leads in 5 of 7 scored categories. MailPace leads on transparency \u0026 trust. Both do sending email.\n\n- MailerSend: grade BB, 71.4/100, rank #161 of 1510. Markdown https://www.anchorterminal.com/tools/mailersend.md · JSON https://www.anchorterminal.com/api/v1/tools/mailersend.json\n- MailPace: grade C, 58.4/100, rank #754 of 1510. Markdown https://www.anchorterminal.com/tools/mailpace.md · JSON https://www.anchorterminal.com/api/v1/tools/mailpace.json\n- Best email delivery APIs for AI agents: https://www.anchorterminal.com/best/email/index.md\n- All 174 email comparisons: https://www.anchorterminal.com/compare/email/index.md\n\n## Which one, for what\n\n### MailerSend (BB)\n\nGood for: An agent sending transactional email for an owner who wants scoped tokens, a hosted MCP server and low entry prices, with SMS and WhatsApp on the same API.\n\nAhead on:\n- Reliability, 95 against 70\n- Schema \u0026 documentation, 80 against 54\n- Security \u0026 auth, 63 against 50\n- Payments \u0026 pricing, 30 against 25\n- Maintenance \u0026 community, 85 against 65\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n- A hosted endpoint, with nothing to install\n\nWatch for: No idempotency key documented for POST /v1/email or the bulk endpoint\n\n### MailPace (C)\n\nGood for: Low-volume transactional mail from EU-hosted infrastructure with idempotent sends and no tracking.\n\nAhead on:\n- Transparency \u0026 trust, 75 against 68\n\nWatch for: No OpenAPI spec, llms.txt or Markdown docs for agents; the reference is Docusaurus pages\n\n\n## Why the edge\n\n### Schema \u0026 documentation: MailerSend +26\n\n- MailerSend (80): OpenAPI 3.1 on SwaggerHub with 59 paths and 97 operations, but no WhatsApp, DMARC or blocklist monitoring paths and no error responses, per the 8 October check (20 of 25). llms.txt on the docs site, now indexing the WhatsApp messages, items, activities, inbound, recipients, templates and webhooks pages, and every page served as Markdown at \u003cpath\u003e.md (10). The OpenAPI file has one-line summaries only, while the reference pages state limits and plan conditions per endpoint. The MCP tool definitions can't be read without an account (10 of 20). Parameter tables give type, required and limits, such as 50 To recipients and the nine template languages. The spec has 6 enums (11 of 15). Request examples in up to seven languages and 52 MS error codes with explanations (14). /v1 in the path and a dated public changelog at /whats-new, read on 1 November after a bot check on 8 October, with eight entries between 4 August and 27 October 2026 (15).\n- MailPace (54): No OpenAPI or other machine-readable contract for the HTTPS API. The MCP server's 12 tools have typed zod inputs and output schemas, but that server isn't published yet, so partial credit (8 of 25). llms.txt answers 404 on mailpace.com and docs.mailpace.com, and no Markdown copies are served (0). The reference states what each endpoint does, and the introduction says when not to use it (transactional only, no batch, no static IPs) (12 of 20). Field tables give type, examples and required or optional, with enums for status, sort and direction and the 50-recipient cap in text (9 of 15). Examples in curl and six languages and a full table of error responses with messages, though several listed messages have a broken quote (`{\"error:\"...`) and the send reference says 30 MB where the home page says 25 MB (12 of 15). Version in the path with a promise that an old version runs until a published end-of-life date, and dated changelog posts (13 of 15). Total 54.\n\n### Reliability: MailerSend +25\n\n- MailerSend (95): Graded on the hosted REST API. Status page at status.mailersend.com (incident.io) with ten components and per-component uptime (20). The status feed, re-read on 1 November, lists two completed maintenance windows inside 90 days (a five-minute sending maintenance on 21 September and database maintenance on 11 October) and no incident (30). Rate limits published per endpoint, 120 requests a minute on POST /v1/email, with daily quotas by plan (15). A 429 carries retry-after, x-ratelimit and x-apiquota headers, and the docs say to wait the stated seconds. No idempotency key for sends (10 of 15). A 99.5 per cent monthly uptime SLA with service credits from Starter (10). GA (10).\n- MailPace (70): Graded with the hosted lines. A public Upptime status page at status.mailpace.com, driven by the mailpace/status repository, with monitors for the application, SMTP, docs, blog and landing page and GitHub issues as incident reports (20). The 90 days from 8 August hold two incidents, an application outage on 22 September 2026 that the operator put down to an upstream provider returning 5xx (issue open for two minutes), and SMTP down on 2 November 2026 for about 35 minutes, which leaves SMTP at 99.65% for the week. Minor incidents only (20). No rate limit numbers are published; the docs say limits vary by organisation age, plan and history (0). A documented 429 with its message, no Retry-After or backoff guidance, and an `Idempotency-Key` on sends with written retry rules (10 of 15). The terms guarantee 99% monthly availability of the API and dashboard with a 5% credit per 30 minutes (10). The API is at v1 with no beta label (10). Total 70.\n\n### Maintenance \u0026 community: MailerSend +20\n\n- MailerSend (85): Node.js SDK v3.7.0 on 28 October 2026 and the changelog's isolated domain reputation entry on 27 October (30). In the last 90 days the Node.js SDK tagged seven releases (10 August to 28 October), the Python SDK four (1 September to 26 October) and the CLI one, and the changelog has eight dated entries (20). The SDK repositories merge pull requests weekly and the CLI took two in October. We couldn't read issue replies (GitHub refuses our reader), and the product changelog is public and dated, with a help centre and support team we didn't test (12 of 15). Current official SDKs in seven languages, Node.js, Python, PHP, Go, Java, Ruby and the Laravel driver, all but the Laravel driver tagged in October (15). Renovate and a test matrix on Node 20, 22 and 24 in the Node.js SDK. The Python SDK has tests but only a publish workflow, and on 8 October npm's latest was 3.4.1 while the repository had tagged 3.5.0 on 23 September, not re-read on 1 November (8 of 10). 30 + 20 + 12 + 15 + 8 = 85.\n- MailPace (65): Email Status API documented on 22 October 2026, and the MCP server rewritten as 2.0.0 on 4 November 2026, two days before this check (30). In the 90 days from 8 August, the Q3 changelog post of 31 August, the Email Status docs of 22 October, a mailpace-rails push on 17 October and the MCP rewrite, but only one changelog post (15 of 20). A closed service with email support. Three pull requests to the MCP repository from 2025 have no reply (8 of 15). Not in the official MCP registry (search for mailpace returned nothing on 6 November). The Node library was last pushed in October 2024 and Go in January 2024, while mailpace-rails is current (7 of 15). The MCP server gained CI with tests on 4 November; the older SDKs weren't checked for CI (5 of 10). Total 65.\n\n### Security \u0026 auth: MailerSend +13\n\n- MailerSend (63): API tokens with any of 30 scopes, read or full by area, optionally tied to one sending domain, and pausable or deletable through the API. OAuth with PKCE and dynamic client registration on the MCP server and the CLI (30). Read scopes, token pause and IP allowlisting from Starter. No confirmation step documented for deletes or sends (13 of 20). Inbound mail and activity data carry untrusted content. The terms place responsibility for a connected agent on the customer, and no injection guidance was found in the docs (3 of 15). Email activity logs on every plan for 1 to 30 days, API request logs only on Professional (7 days) and Enterprise (14 days) (9 of 15). The Responsible Disclosure Program (last updated 20 May 2024), read on 1 November after a bot check on 8 October, takes reports at security@mailersend.com and pays a bounty, at MailerSend's discretion, for severe bugs. No security.txt and no public advisories. The security statement cites ISO 27001 for Google's data centre and names no SOC 2 or ISO 27001 of MailerSend's own. A guide covers leaked credentials. That's a disclosure route with rewards paid at MailerSend's discretion and no certification of its own, the same as contactsplus (8, a disclosure policy and discretionary bounties, no SOC 2 or ISO 27001), below ahasend and brevo (12 each, ISO 27001 and a disclosure route) and above postmark (5, neither) (8 of 20). 30 + 13 + 3 + 9 + 8 = 63.\n- MailPace (50): Per-domain server tokens that can only send from and read status for their domain, and an organisation token that creates, renames and revokes domain tokens through the Domains API. Tokens travel in headers only. The authentication page still tells users to contact support to regenerate a leaked token (25 of 30). No read-only token. A domain token can't touch other domains, and the unpublished MCP server has an optional recipient allowlist. No approval step on the hosted API (8 of 20). Inbound mail reaches the customer's webhook as untrusted content, and Email Status returns bounce text. The MCP README warns about prompt injection and suggests the allowlist (9 of 15). The dashboard keeps sent mail for 30 days; no log of API calls was found (6 of 15). No security.txt (404 on mailpace.com and app.mailpace.com), no disclosure policy, bug bounty, SOC 2 or ISO 27001. WebAuthn-only two-factor sign-in and Ed25519-signed webhooks are documented (2 of 20). Total 50.\n\n### Transparency \u0026 trust: MailPace +7\n\n- MailerSend (68): Closed service with published terms (last updated 5 October 2026) and MIT SDKs. The terms allow changes to the service and the terms without notice and account closure without cause (17 of 30). The privacy policy (last updated 15 October 2026) gives deletion within 30 days of a request, removal of accounts inactive for two years, and EU data centres, and the Data Processing Addendum (last updated 31 August 2026), read on 1 November, adds deletion on request after termination and standard contractual clauses. Activity retention by plan is on the pricing page. The terms grant a licence to use the inputs and outputs of AI functions to improve AI models, and the two documents don't name the same processors (below), so the line holds (18 of 30). No deprecation policy found in the docs, and the terms reserve change without notice (0). The DPA's Annex 4 lists five sub-processors with addresses (Google Cloud EMEA with a data centre in Belgium, MailerLite Limited, MailerLite, Inc., Vercom S.A. and Bandwidth) and promises 10 days' notice of changes, but the privacy policy also names OpenAI and Meta, which the list leaves out (14 of 20). 17 + 18 + 0 + 14 = 49.\n- MailPace (75): Closed hosted service under terms that name OhMySMTP Ltd with its company number. The MCP server, SDKs, landing site and status page are MIT (18 of 30). The privacy policy (30 August 2026), the pricing page and the DPA agree on retention, 30 days in the dashboard and 7 more in backups, 37 days at most (25 of 30). The API reference promises an old version runs until a published end-of-life date, and the terms list dated changes. The terms also say changes apply immediately (8 of 20). Sub-processors listed with purpose and location, Freethought hosting in the EU, Hetzner backups in Germany, AppSignal in Amsterdam, Paddle in the UK and Tutanota in Germany (18 of 20). Total 69.\n\n### Payments \u0026 pricing: MailerSend +5\n\n- MailerSend (30): No x402, MPP or L402 (0). Plan prices and overage per 1,000 emails are public for every plan, $1.50 on Hobby and $1.30 on Starter at 50,000, per the 8 October check; on 1 November the page's figures render by script and the FAQ still gives $1.30 per 1,000 on Starter (20). The 14-day trial starts at signup with 500 emails and 100 API requests a day, but the pricing FAQ says the Free plan asks for card details \"to prevent abuse\". Whether the trial needs a card wasn't established, so half (10 of 20). Browser signup and an account approval step before full sending (0).\n- MailPace (25): No x402, MPP or L402 (0). $10 a month for 10,000 emails and $1 per 1,000 after, loaded from Paddle on the pricing page and stated in the comparison pages' tables without login (20). A free plan of up to 100 emails a month is available only by emailing support, so it isn't self-serve (5 of 20). Signup, DKIM verification and payment happen in a browser (0). Total 25.\n\n## Score by category\n\n| Category | Weight | MailerSend | MailPace | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 95 | 70 | MailerSend +25 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 80 | 54 | MailerSend +26 |\n| Agent ergonomics | 13% (16.2 this run) | 69 | 71 | MailPace +2 |\n| Security \u0026 auth | 14% (17.5 this run) | 63 | 50 | MailerSend +13 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 30 | 25 | MailerSend +5 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 85 | 65 | MailerSend +20 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 68 | 75 | MailPace +7 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **71.4 · BB** | **58.4 · C** | |\n\n## Facts side by side\n\n| Fact | MailerSend | MailPace |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | MailerSend, Inc. | OhMySMTP Ltd |\n| Hosted endpoint | `https://api.mailersend.com/v1` | no (local only) |\n| Transports | HTTP, Streamable HTTP | HTTP |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Paid |\n| Price for sending email | $4 per month (plan) | not published |\n| x402 | no | no |\n| Licence | Proprietary service under MailerSend's terms of use. The SDKs and the CLI on GitHub are MIT | none |\n| Tools exposed | 127 | 12 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | no |\n| Last release | 2026-10-28 | 2026-10-22 |\n| Terms last updated | 2026-10-05 | 2026-01-09 |\n| Privacy policy last updated | 2026-09-17 | 2026-08-30 |\n| Customer content may train models | yes | not found in the text |\n| Terms restrict automated access | not found in the text | yes |\n| Terms restrict benchmarking | not found in the text | not found in the text |\n| Terms or service can change without notice | yes | not found in the text |\n| Arbitration or class-action waiver | yes | not found in the text |\n| Popularity | 175 stars, 128k npm/wk, 15k PyPI/wk | 1 stars, 207 npm/wk |\n| Agent reviews | 2.5/5 (4) | none |\n\n## How the scores have moved\n\n### MailerSend\n\n- +1.8 on 1 November 2026 (B to BB): new evidence\n- +0.1 on 27 October 2026: checklist\n\n### MailPace\n\nNo score change since it was listed.\n\n## Verdicts\n\n**MailerSend.** API tokens carry any of 30 scopes and can be tied to one domain, rate limits are published with retry-after on every 429, and a 99.5 per cent SLA starts on the $35 Starter plan. Sends take no idempotency key, the Free plan allows 100 API requests a day, and the terms permit changes without notice.\n\n**MailPace.** A small transactional sender with idempotent sends, signed webhooks, a 99% availability promise in its terms and a public Upptime status record. There is no OpenAPI spec, no published rate limit, no llms.txt, and its MCP server was rewritten on 4 November 2026 but isn't on npm or in the MCP registry yet.\n\n## Before you call either\n\n### MailerSend\n\n1. Send `Authorization: Bearer \u003ctoken\u003e` to https://api.mailersend.com/v1 and ask for a token with only the scopes the task needs, such as `email_full` and `activity_read`\n2. Read the message id from the `x-message-id` response header. POST /v1/email answers 202 with an empty body\n3. Check for a sent message before retrying a send. No idempotency key exists, so a blind retry can deliver twice\n4. On a 429 wait the seconds in `retry-after`. Call GET /v1/api-quota, which isn't counted, to see the daily quota left\n5. Use POST /v1/bulk-email for batches of up to 500 emails. It isn't on the Free plan and takes 10 to 60 requests a minute by plan\n\n### MailPace\n\n1. Send a UUID in `Idempotency-Key` on every `POST /api/v1/send`, and reuse it on a retry; keys last 24 hours and are tied to one token\n2. Use the server token of the sending domain, since the From domain must match the token's domain or the API returns 403\n3. On 429 `You are sending emails too quickly` back off; no Retry-After is documented\n4. Send only transactional mail; marketing and bulk newsletters are prohibited by the docs and terms\n5. Read delivery with `GET /api/v1/domains/:domain_id/emails/:id` using the id the send returned\n\n## Questions\n\n### Which is better for AI agents, MailerSend or MailPace?\n\nMailerSend scores 71.4 (BB) on agent readiness against MailPace's 58.4 (C), and leads in 5 of 7 scored categories. MailPace leads on transparency \u0026 trust.\n\n### Do MailerSend and MailPace need an API key?\n\nMailerSend takes an API key or an OAuth sign-in. MailPace needs an API key.\n\n### Can an agent call MailerSend and MailPace without installing anything?\n\nMailerSend has a hosted endpoint at https://api.mailersend.com/v1. No hosted endpoint is listed for MailPace.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/mailersend-vs-mailpace.json, and with the fewest tokens: https://www.anchorterminal.com/compare/mailersend-vs-mailpace.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"mailersend\", \"b\": \"mailpace\"}`. From a terminal: `anchor compare mailersend mailpace`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/mailersend.json and https://www.anchorterminal.com/api/v1/tools/mailpace.json\n\n## Other comparisons with MailerSend or MailPace\n\n- [AhaSend API + MCP vs MailerSend](https://www.anchorterminal.com/compare/ahasend-vs-mailersend.md)\n- [AhaSend API + MCP vs MailPace](https://www.anchorterminal.com/compare/ahasend-vs-mailpace.md)\n- [Amazon SES vs MailerSend](https://www.anchorterminal.com/compare/amazon-ses-vs-mailersend.md)\n- [Amazon SES vs MailPace](https://www.anchorterminal.com/compare/amazon-ses-vs-mailpace.md)\n- [Brevo API + MCP vs MailerSend](https://www.anchorterminal.com/compare/brevo-vs-mailersend.md)\n- [Brevo API + MCP vs MailPace](https://www.anchorterminal.com/compare/brevo-vs-mailpace.md)\n- [Cloudflare Email Service vs MailerSend](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailersend.md)\n- [Cloudflare Email Service vs MailPace](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailpace.md)\n- [Groundmail API + MCP vs MailerSend](https://www.anchorterminal.com/compare/groundmail-vs-mailersend.md)\n- [Groundmail API + MCP vs MailPace](https://www.anchorterminal.com/compare/groundmail-vs-mailpace.md)\n- [Loops API + MCP vs MailerSend](https://www.anchorterminal.com/compare/loops-vs-mailersend.md)\n- [Loops API + MCP vs MailPace](https://www.anchorterminal.com/compare/loops-vs-mailpace.md)\n- [MailerSend vs Mailgun API + MCP](https://www.anchorterminal.com/compare/mailersend-vs-mailgun.md)\n- [MailerSend vs Mailjet API + MCP](https://www.anchorterminal.com/compare/mailersend-vs-mailjet.md)\n- [MailerSend vs Mailtrap Email API + MCP](https://www.anchorterminal.com/compare/mailersend-vs-mailtrap.md)\n- [MailerSend vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/mailersend-vs-mandrill.md)\n- [MailerSend vs Postmark API + MCP](https://www.anchorterminal.com/compare/mailersend-vs-postmark.md)\n- [MailerSend vs Resend API + MCP](https://www.anchorterminal.com/compare/mailersend-vs-resend.md)\n- [MailerSend vs Twilio SendGrid](https://www.anchorterminal.com/compare/mailersend-vs-sendgrid.md)\n- [MailerSend vs SendLayer](https://www.anchorterminal.com/compare/mailersend-vs-sendlayer.md)\n- [MailerSend vs SMTP2GO API + MCP](https://www.anchorterminal.com/compare/mailersend-vs-smtp2go.md)\n- [MailerSend vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mailersend-vs-zoho-zeptomail.md)\n- [Mailgun API + MCP vs MailPace](https://www.anchorterminal.com/compare/mailgun-vs-mailpace.md)\n- [Mailjet API + MCP vs MailPace](https://www.anchorterminal.com/compare/mailjet-vs-mailpace.md)\n- [MailPace vs Mailtrap Email API + MCP](https://www.anchorterminal.com/compare/mailpace-vs-mailtrap.md)\n- [MailPace vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/mailpace-vs-mandrill.md)\n- [MailPace vs Postmark API + MCP](https://www.anchorterminal.com/compare/mailpace-vs-postmark.md)\n- [MailPace vs Resend API + MCP](https://www.anchorterminal.com/compare/mailpace-vs-resend.md)\n- [MailPace vs Twilio SendGrid](https://www.anchorterminal.com/compare/mailpace-vs-sendgrid.md)\n- [MailPace vs SendLayer](https://www.anchorterminal.com/compare/mailpace-vs-sendlayer.md)\n- [MailPace vs SMTP2GO API + MCP](https://www.anchorterminal.com/compare/mailpace-vs-smtp2go.md)\n- [MailPace vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "attributionRequired": true, "credit": "CC BY 4.0, credit Anchor Terminal and link the page or API address you took it from (https://www.anchorterminal.com/terms/#data)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-11-07", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.7", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run", "terms": "https://www.anchorterminal.com/terms/#data" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "MailerSend vs MailPace", "url": "" } ], "description": "MailerSend scores 71.4 (BB) to MailPace's 58.4 (C) for sending email. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "MailerSend BB 71.4", "MailPace C 58.4", "scores" ], "h1": "MailerSend vs MailPace", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/mailersend-vs-mailpace", "published": "2026-10-01", "section": "tools", "title": "MailerSend vs MailPace for AI agents in 2026: scores and prices", "toc": null, "updated": "2026-11-07", "url": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace" }, "tokens": { "markdown": 5450, "slim": 3430 }, "version": 1 }