{ "data": { "a": { "slug": "groundmail", "name": "Groundmail API + MCP", "vendor": "Groundmail", "vendorUrl": "https://groundmail.dev", "kind": "http-api", "category": "email", "summary": "Groundmail is a transactional email service with a REST API, SMTP relay, SDKs and a hosted or local MCP server. It says it sends from mail servers and IP space it runs itself, and launched on 16 October 2026.", "url": "https://www.anchorterminal.com/tools/groundmail", "markdownUrl": "https://www.anchorterminal.com/tools/groundmail.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/groundmail.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/groundmail.json", "dns": "groundmail.grade.anchorterminal.com", "repo": "https://github.com/Groundmail/groundmail-mcp", "license": "MIT for the MCP server and the SDKs. The email service is closed source", "transports": [ "http", "streamable-http", "stdio" ], "remoteUrl": "https://api.groundmail.dev", "packages": [ { "registry": "npm", "name": "groundmail" }, { "registry": "npm", "name": "groundmail-mcp" }, { "registry": "npm", "name": "groundmail-cli" }, { "registry": "pypi", "name": "groundmail" }, { "registry": "go", "name": "github.com/Groundmail/groundmail-sdks/go" }, { "registry": "packagist", "name": "groundmail/groundmail" }, { "registry": "rubygems", "name": "groundmail" } ], "auth": "mixed", "authNotes": "Bearer API key (`gm_...`) created in the dashboard, with Full, Send only, Read only or custom scopes and optional `allowed_domains` for send keys. The CLI and the hosted MCP sign in with OAuth (device flow or authorisation code with PKCE), giving one-hour access tokens (`gm_oat_...`) and rotating refresh tokens. The SMTP relay uses separate `gmsmtp_...` credentials.", "pricing": "freemium", "pricingNotes": "Free plan with 3,000 emails a month, 100 a day and three sending domains, never charged, with no card to sign up but a card on file needed to send to anyone but the account email. Pay as you go is $15 a month with 20,000 emails included, then $0.70 per 1,000 to 100,000, $0.50 to 1 million and $0.30 above (sent and received count the same). Dedicated server $299 a month with 250,000 emails, then $0.40 per 1,000. Accounts on the earlier Pro and Scale plans keep them (https://groundmail.dev/pricing/).", "priceSummary": "$15 / mo", "where": "both", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in llms-full.txt, the OpenAPI document or the pricing page (checked 2026-10-17). Billing is through Stripe.", "endpoints": [] }, "toolCount": 20, "popularity": { "githubStars": null, "npmWeekly": null, "pypiWeekly": null, "asOf": "2026-10-17" }, "docsUrl": "https://docs.groundmail.dev", "llmsTxt": "https://docs.groundmail.dev/llms.txt", "openapi": "https://docs.groundmail.dev/openapi.yaml", "registryName": "io.github.Groundmail/groundmail", "capabilities": [ "email.send", "email.domains", "email.templates", "email.inbound", "email.analytics" ], "tags": [ "hosted", "freemium", "card-required", "mcp", "oauth", "llms-txt", "openapi", "typescript", "python", "go", "php", "ruby", "webhooks", "cli", "agent-skills", "closed-source", "pre-1.0", "new" ], "lastRelease": "2026-11-04", "graded": true, "anchor": { "graded": true, "score": 64.5, "grade": "B", "agentReady": false, "rank": 462, "ranked": true, "rankOf": 1510, "categoryRank": 11, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 69, "maintenance": 77, "payments": 35, "reliability": 68, "schema": 88, "security": 63, "transparency": 71 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-04" }, "negative": -3, "negativeNotes": [ "-3, published API behaviour changed for existing clients with word only on the day it took effect. On 3 November 2026 the changelog said each `to`, `cc`, `bcc` and `from` entry must now be one address, so a list in one string now gets `validation_error`, and that webhook URLs on private addresses are refused, with existing endpoints there now showing `blocked destination`. On 2 November a batch that doesn't fit the request rate is refused whole, and on 18 October the new-account limit moved to a `daily_ramp_limit` 429. One folded term. https://groundmail.dev/changelog/" ], "verdict": "Groundmail pairs scoped API keys and OAuth with stable error codes, recovery hints and `Idempotency-Key` on sends, and its 51 MCP tools carry safety annotations. Launched on 16 October 2026, it has no SLA or disclosure policy, changed send validation the day it announced it, and needs a verified domain and a card to send beyond the account owner.", "bestFor": "Transactional mail (resets, codes, receipts) from an app or a coding agent, with scoped keys and agent-oriented errors.", "strengths": [ "Every error carries a stable `code`, a `hint`, a `docs_url` and, for scope failures, the `required_scope`", "`Idempotency-Key` on single and batch sends and on /events, kept 24 hours, with the 504 outcome-unknown case documented", "Scoped API keys (Full, Send only, Read only or custom) and send keys limited to named domains", "A public status page with nine components and a dated changelog with an RSS feed, both started after launch", "All MCP tools carry readOnly, destructive and idempotent hints and an output schema" ], "weaknesses": [ "51 MCP tools with no toolsets, about 114 KB of definitions and output schemas", "A card on file is needed to send to anyone but the account email, including on the Free plan", "No SLA, disclosure policy, bug bounty or certification; security.txt names only a support address", "Stricter `to` and `from` checks and the private-address webhook block took effect the day they were posted (3 November 2026)", "The MCP `send_email` tool takes no idempotency key, so a retried tool call can send twice" ], "agentNotes": [ "Send an `Idempotency-Key` on raw POST /emails or /emails/batch and reuse it on retries. On 504, check GET /emails before sending again", "Pass several recipients as an array. A list in one `to` string now returns `validation_error`", "Ask the person before adding a domain or a card. Both are needed before mail reaches other recipients", "On 429 `daily_ramp_limit`, wait until `details.resets_at`. The new-account limit doubles only after clean sending", "Request only the scopes needed, such as `emails:send`. An OAuth request with no scope gets `full`" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 4, "avgRating": 2.5, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "B", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 64.5 } ], "editorialScores": { "ergonomics": 69, "maintenance": 77, "payments": 35, "reliability": 68, "schema": 88, "security": 63, "transparency": 59 }, "provenanceScore": 83, "checked": { "categories": { "ergonomics": "2026-11-04", "maintenance": "2026-11-04", "payments": "2026-11-04", "reliability": "2026-11-04", "schema": "2026-11-04", "security": "2026-11-04", "transparency": "2026-11-04" }, "last": "2026-11-04", "lastMoved": "2026-11-04", "oldest": "2026-11-04", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "npm install groundmail", "http": "curl -X POST https://api.groundmail.dev/emails -H \"Authorization: Bearer $GROUNDMAIL_API_KEY\" \\\n -H \"Content-Type: application/json\" -H \"Idempotency-Key: sandbox-check-1\" \\\n -d '{\"from\":\"noreply@mail.groundmail.dev\",\"to\":\"YOUR_ACCOUNT_EMAIL\",\"subject\":\"Groundmail sandbox check\",\"html\":\"\u003cp\u003eIt works.\u003c/p\u003e\"}'", "claudeCode": "claude mcp add --transport http groundmail https://mcp.groundmail.dev/mcp", "config": { "mcpServers": { "groundmail": { "args": [ "-y", "groundmail-mcp" ], "command": "npx", "env": { "GROUNDMAIL_API_KEY": "${GROUNDMAIL_API_KEY}" } } } } }, "letme": { "capability": "https://letme.dev/email.send", "tool": "https://letme.dev/groundmail" }, "area": "communication", "unitPrices": [ { "item": "Pay as you go", "unit": "month", "usd": 15, "note": "20,000 emails included, sent or received" }, { "item": "Emails 20,000 to 100,000", "unit": "1k-emails", "usd": 0.7 }, { "item": "Emails 100,000 to 1 million", "unit": "1k-emails", "usd": 0.5 }, { "item": "Emails above 1 million", "unit": "1k-emails", "usd": 0.3 }, { "item": "Dedicated server", "unit": "month", "usd": 299, "note": "250,000 emails included, $0.40 per 1,000 after" }, { "item": "Extra dedicated IP", "unit": "month", "usd": 25, "note": "One IP included from 100,000 emails a month on pay as you go" } ], "provenance": { "legalEntity": "Power Only Transit Inc. dba Groundmail", "domain": "groundmail.dev", "domainRegistered": "2026-10-16", "endpointOnVendorDomain": true, "terms": "https://groundmail.dev/legal/terms/", "privacy": "https://groundmail.dev/legal/privacy/", "statusPage": "https://status.groundmail.dev/", "changelog": "https://groundmail.dev/changelog/", "securityTxt": "valid", "checked": "2026-11-04", "notes": [ "The terms, privacy policy, DPA and subprocessor list name Power Only Transit Inc. dba Groundmail, 2780 S. Jones Blvd #200-3432, Las Vegas, NV 89146, and Delaware law.", "RDAP gave groundmail.dev a registration time of 2026-10-16T03:15Z (17 October check). The terms say they were last updated on 3 November 2026 (v2026-10), the acceptable use policy on 8 August 2026.", "groundmail.dev serves a security.txt with a support contact, expiring 2027-10-20. status.groundmail.dev has nine components since 19 October 2026 and a changelog is at groundmail.dev/changelog/.", "robots.txt allows all on groundmail.dev and status.groundmail.dev (bar admin and subscription paths) and disallows only /api/ on docs.groundmail.dev. Only allowed paths were read." ], "score": 83 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/groundmail.json", "live": { "slug": "groundmail", "probe": { "target": "https://api.groundmail.dev", "method": "get", "lastAt": "2026-11-07T22:56:00.530118169Z", "lastOk": true, "lastStatus": 200, "lastMs": 758, "authRequired": false, "uptime24h": 100, "uptime30d": 99.96, "p50ms24h": 685, "p95ms24h": 894, "samples24h": 244, "samples30d": 5191, "days": [ { "date": "2026-10-17", "probes": 21, "ok": 21 }, { "date": "2026-10-18", "probes": 256, "ok": 256 }, { "date": "2026-10-19", "probes": 255, "ok": 254 }, { "date": "2026-10-20", "probes": 252, "ok": 252 }, { "date": "2026-10-21", "probes": 253, "ok": 252 }, { "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": 233, "ok": 233 } ] }, "vendorStatus": { "page": "https://status.groundmail.dev", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:47:52.941501744Z" }, "versions": [ { "registry": "mcp-registry", "name": "io.github.Groundmail/groundmail", "version": "0.29.4", "seenAt": "2026-11-07T18:16:28.95801333Z" }, { "registry": "npm", "name": "groundmail", "version": "0.47.0", "seenAt": "2026-11-06T23:31:35.759972555Z" }, { "registry": "npm", "name": "groundmail-cli", "version": "0.45.0", "seenAt": "2026-11-06T23:31:38.174976058Z" }, { "registry": "npm", "name": "groundmail-mcp", "version": "0.29.2", "seenAt": "2026-11-06T23:31:36.080222949Z" }, { "registry": "pypi", "name": "groundmail", "version": "0.8.4", "released": "2026-10-18", "seenAt": "2026-11-06T23:31:40.214692816Z" } ], "githubStars": 0, "npmWeekly": 5783, "pypiWeekly": 15, "securityTxt": { "url": "https://groundmail.dev/.well-known/security.txt", "state": "valid", "expires": "2027-10-20T00:00:00.000Z", "checkedAt": "2026-11-07T16:00:56.088942568Z" }, "llmsTxt": { "url": "https://docs.groundmail.dev/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:32:39.528449172Z" }, "domain": { "domain": "groundmail.dev", "registered": "2026-10-16", "source": "https://pubapi.registry.google/rdap/domain/groundmail.dev", "checkedAt": "2026-11-01T14:07:48.376499947Z" }, "pages": [ { "url": "https://groundmail.dev/changelog/", "kind": "changelog", "status": 200, "checkedAt": "2026-11-07T14:10:39.827251004Z", "changedAt": "2026-11-07T14:10:39.827251004Z", "fingerprint": "db85a9f91eba" }, { "url": "https://groundmail.dev/pricing/", "kind": "pricing", "status": 200, "checkedAt": "2026-11-07T14:10:46.083268939Z", "changedAt": "2026-11-07T14:10:46.083268939Z", "fingerprint": "31d5131b2f71" }, { "url": "https://groundmail.dev/legal/privacy/", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:10:42.736453053Z", "changedAt": "2026-11-07T14:10:42.736453053Z", "fingerprint": "c8f5eef53128" }, { "url": "https://groundmail.dev/legal/terms/", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:10:44.067602418Z", "changedAt": "2026-11-07T14:10:44.067602418Z", "fingerprint": "f962741bb2c0" } ], "mcpTools": { "url": "https://mcp.groundmail.dev/mcp", "checkedAt": "2026-11-07T01:45:18.138300666Z", "status": "auth", "note": "asks for credentials before listing its tools", "changedAt": "2026-11-07T01:45:18.138300666Z" }, "github": { "repo": "groundmail/groundmail-mcp", "checkedAt": "2026-11-02T08:53:16.530414143Z", "stars": 0, "archived": false, "issuesEnabled": true, "pushedAt": "2026-11-02T04:35:38Z", "openIssues": 0, "openPRs": 0, "issuesOpened90d": 0, "issuesClosed90d": 0, "prsMerged90d": 0 }, "updatedAt": "2026-11-07T22:56:00.530118169Z" } }, "answer": "Groundmail API + MCP scores 64.5 (B) on agent readiness against SendLayer's 47.7 (D), and leads in every scored category.", "b": { "slug": "sendlayer", "name": "SendLayer", "vendor": "SendLayer, LLC", "vendorUrl": "https://sendlayer.com", "kind": "http-api", "category": "email", "summary": "SendLayer is a transactional email service from SendLayer, LLC, with an SMTP relay, a REST API for sending and email events, webhooks, SDKs in five languages and a hosted MCP server. It is aimed largely at WordPress and small-business sites.", "url": "https://www.anchorterminal.com/tools/sendlayer", "markdownUrl": "https://www.anchorterminal.com/tools/sendlayer.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/sendlayer.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/sendlayer.json", "dns": "sendlayer.grade.anchorterminal.com", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://mcp.sendlayer.com", "packages": [ { "registry": "npm", "name": "sendlayer" }, { "registry": "pypi", "name": "sendlayer" } ], "auth": "api-key", "authNotes": "Bearer API key in the `Authorization` header, created per sending domain in the dashboard (one is made when a domain is authorised). Keys can be labelled and deleted; no scopes or read-only keys were found. The hosted MCP server takes the same key in an `x-sendlayer-api-key` or `Authorization` header.", "pricing": "paid", "pricingNotes": "Plans billed annually. Starter $5 a month for 1,000 emails, Business $15 for 5,000, Growth $25 for 10,000, Scale 20,000+ by quote. A free trial sends up to 200 emails. Accounts that reach their limit are upgraded automatically. 14-day money-back guarantee.", "priceSummary": "$5 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the developer docs, llms.txt, the OpenAPI file or the pricing page (checked 2026-11-06).", "endpoints": [] }, "toolCount": 5, "popularity": { "githubStars": null, "npmWeekly": 113, "pypiWeekly": 9, "asOf": "2026-11-06" }, "docsUrl": "https://developers.sendlayer.com/", "llmsTxt": "https://developers.sendlayer.com/llms.txt", "openapi": "https://developers.sendlayer.com/api-reference/sendlayer.json", "capabilities": [ "email.send", "email.analytics", "email.domains" ], "tags": [ "hosted", "closed-source", "smtp", "webhooks", "openapi", "llms-txt", "mcp", "remote-mcp", "status-page", "typescript", "python", "php", "ruby", "go" ], "lastRelease": "2026-08-21", "graded": true, "anchor": { "graded": true, "score": 47.7, "grade": "D", "agentReady": false, "rank": 1148, "ranked": true, "rankOf": 1510, "categoryRank": 19, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 62, "maintenance": 40, "payments": 20, "reliability": 48, "schema": 68, "security": 38, "transparency": 49 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-06" }, "negative": 0, "verdict": "A small API with an OpenAPI file, llms.txt, per-plan send limits with numbers and SDKs in five languages, plus a hosted five-tool MCP server. Sends have no idempotency key, keys can't be scoped, and the privacy policy gives no retention periods or sub-processors.", "bestFor": "Low-volume transactional mail for WordPress and small sites.", "strengths": [ "Send limits per minute, hour and day are published for each plan", "OpenAPI file, llms.txt and Markdown copies of every developer page", "Official SDKs for Node, Python, PHP, Ruby and Go", "Hosted MCP server at mcp.sendlayer.com with five tools for sending, events and webhooks", "Numbered error codes with messages for each missing or invalid field" ], "weaknesses": [ "No idempotency key on sends, so a retried request can send twice", "API keys can't be scoped or made read-only", "Status history shows 98 automated outage entries in 90 days with no durations or write-ups", "Privacy policy has no date, retention periods, DPA or sub-processor list", "No public changelog, SLA, security.txt or disclosure policy found" ], "agentNotes": [ "Check the email log with `GET /api/v1/events` before retrying a failed send, since sends have no idempotency key", "Keep To and CC at 10 addresses or fewer and BCC at 5, or the API returns error code 20 or 27", "Pace sends to the plan's per-minute limit, 50 on Starter and 120 on Business, and back off on 429", "Pass the API key in a header to mcp.sendlayer.com; the server answers 405 to anything but POST" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "D", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 47.7 } ], "editorialScores": { "ergonomics": 62, "maintenance": 40, "payments": 20, "reliability": 48, "schema": 68, "security": 38, "transparency": 23 }, "provenanceScore": 75, "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": { "install": "npm install sendlayer", "http": "curl https://console.sendlayer.com/api/v1/email -X POST -H \"Authorization: Bearer $SENDLAYER_API_KEY\" -H \"Content-Type: application/json\" -d '{\"From\":{\"name\":\"You\",\"email\":\"you@yourdomain.com\"},\"To\":[{\"name\":\"Person\",\"email\":\"person@example.com\"}],\"Subject\":\"Hello\",\"ContentType\":\"Text\",\"PlainContent\":\"Hello\"}'", "claudeCode": "claude mcp add --scope user --transport http sendlayer-mcp https://mcp.sendlayer.com --header \"Authorization: Bearer YOUR_SENDLAYER_API_KEY\"", "config": { "mcpServers": { "sendlayer": { "headers": { "x-sendlayer-api-key": "YOUR_SENDLAYER_API_KEY" }, "url": "https://mcp.sendlayer.com" } } } }, "letme": { "capability": "https://letme.dev/email.send", "tool": "https://letme.dev/sendlayer" }, "area": "communication", "unitPrices": [ { "item": "Starter", "unit": "month", "usd": 5, "note": "1,000 emails a month, billed annually" }, { "item": "Business", "unit": "month", "usd": 15, "note": "5,000 emails a month, billed annually" }, { "item": "Growth", "unit": "month", "usd": 25, "note": "10,000 emails a month, billed annually" } ], "provenance": { "legalEntity": "SendLayer, LLC", "domain": "sendlayer.com", "domainRegistered": "2015-07-22", "endpointOnVendorDomain": true, "terms": "https://sendlayer.com/terms-of-service/", "privacy": "https://sendlayer.com/privacy-policy/", "statusPage": "https://status.sendlayer.com", "changelog": "", "securityTxt": "none", "checked": "2026-11-06", "notes": [ "The terms name SendLayer, LLC under Florida law with courts in West Palm Beach. Neither the terms nor the privacy policy carries a date.", "The terms contain no clause on automated access to the website.", "sendlayer.com/robots.txt disallows only WordPress internals, cart and search paths. developers.sendlayer.com allows all but /_next/ and /cdn-cgi/.", "RDAP gives sendlayer.com a registration date of 22 July 2015; the about page says the team started SendLayer in 2022, and the footer copyright runs from 2021.", "/.well-known/security.txt returns 404." ], "score": 75 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/sendlayer.json", "live": { "slug": "sendlayer", "probe": { "target": "https://mcp.sendlayer.com", "method": "get", "lastAt": "2026-11-07T22:56:20.444245885Z", "lastOk": true, "lastStatus": 405, "lastMs": 460, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 334, "p95ms24h": 425, "samples24h": 244, "samples30d": 246, "days": [ { "date": "2026-11-06", "probes": 13, "ok": 13 }, { "date": "2026-11-07", "probes": 233, "ok": 233 } ] }, "vendorStatus": { "page": "https://status.sendlayer.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:48:44.410046578Z" }, "versions": [ { "registry": "npm", "name": "sendlayer", "version": "1.1.0", "seenAt": "2026-11-07T00:04:36.013206716Z" }, { "registry": "pypi", "name": "sendlayer", "version": "1.1.0", "released": "2026-08-21", "seenAt": "2026-11-07T00:04:36.403864413Z" } ], "npmWeekly": 113, "pypiWeekly": 9, "securityTxt": { "url": "https://sendlayer.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-11-07T16:00:08.464258052Z" }, "llmsTxt": { "url": "https://developers.sendlayer.com/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:33:54.535300528Z" }, "pages": [ { "url": "https://sendlayer.com/privacy-policy/", "kind": "privacy", "status": 200, "checkedAt": "2026-11-07T14:19:27.507195007Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "1f5bea738989" }, { "url": "https://sendlayer.com/terms-of-service/", "kind": "terms", "status": 200, "checkedAt": "2026-11-07T14:19:31.497088663Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "1fbf9877b12a" } ], "mcpTools": { "url": "https://mcp.sendlayer.com", "checkedAt": "2026-11-07T01:47:41.040426143Z", "status": "auth", "note": "asks for credentials before listing its tools", "changedAt": "2026-11-07T01:47:41.040426143Z" }, "updatedAt": "2026-11-07T22:56:20.444245885Z" } }, "edges": [ { "by": 37, "category": "maintenance", "leads": "groundmail", "name": "Maintenance \u0026 community", "reasons": { "a": "groundmail-mcp 0.27.0, published to the official MCP registry on 4 November 2026 (30). The official MCP registry lists 42 groundmail-mcp versions published from 18 October to 4 November on the first page of its listing, the Go SDK is tagged to go/v0.9.2 (23 October), and the changelog has 155 dated entries, 136 of them since 16 October (20). The public GitHub repositories are mirrors with no readable issue replies, and support is by email and in-product chat whose replies weren't read; the public changelog is new since 17 October (8 of 25, judgement call). In the official MCP registry under the GitHub-verified namespace io.github.Groundmail, with current SDKs (15). Tests in the MCP and SDK repositories and a current MCP SDK dependency (^1.32.2), but no CI workflow in the public repositories (4 of 10). 30+20+8+15+4 = 77.", "b": "The Node and Python SDKs were last released as 1.1.0 on 21 August 2026, 77 days before this check (20). One SDK release in the 90 days and no dated changelog (0 of 20). A closed service with a support form and docs updated through 2026, but no public changelog (5 of 15). Not in the official MCP registry (search for sendlayer returned nothing on 6 November). Official SDKs in five languages (10 of 15). The SDK repositories exist on GitHub under sendlayer; their CI wasn't read (5 of 10). Total 40." }, "scores": { "a": 77, "b": 40 } }, { "by": 25, "category": "security", "leads": "groundmail", "name": "Security \u0026 auth", "reasons": { "a": "Scoped API keys with Full, Send only, Read only and custom sets, send keys limited to named domains, and OAuth with PKCE S256, resource indicators, one-hour tokens and refresh-token reuse detection. Bearer tokens go in the header only. An OAuth request that names no scope gets `full` (28 of 30). Read-only and send-only presets for keys and MCP connections, and the sandbox limits sends to the account email until a domain and card are on file. Confirmation before a send is left to the client (16 of 20). The MCP returns subjects and bounce reasons, and the API returns full inbound messages from /received-emails. No prompt-injection guidance in the MCP source or README (4 of 15). Connected CLIs and agents are listed with their scopes and can be revoked, keys show `last_used_at`, GET /emails logs each send, and since 3 November a webhook delivery log shows every attempt. No request or audit log is documented (8 of 15). groundmail.dev now serves a security.txt (contact support@groundmail.dev, expires 20 October 2027) with no acknowledgement time, no disclosure policy, bug bounty or certification found; graded as mails-ai and tokenrip (7 of 20). 28+16+4+8+7 = 63.", "b": "Plain revocable API keys per domain, several allowed, sent in a header; no scopes, expiry or rotation feature beyond creating and deleting keys (20 of 30). No read-only key or approval step (0 of 20). The API returns event data, not received mail (10 of 15). Email logs kept 3, 15 or 30 days by plan, and no log of API calls was found (8 of 15). No security.txt (404), disclosure policy, bug bounty or certification found (0 of 20). Total 38." }, "scores": { "a": 63, "b": 38 } }, { "by": 22, "category": "transparency", "leads": "groundmail", "name": "Transparency \u0026 trust", "reasons": { "a": "Closed service with published terms (updated 3 November 2026), and the MCP server and SDKs under MIT (20 of 30). Since 22 October retention is published per plan (7 days on Free, 30 on Pro, 90 on Scale and pay as you go, up to a year on Dedicated), and since 3 November a DPA with the EU Standard Contractual Clauses and a 48-hour incident notice and a public subprocessor list are published. The privacy policy still says message logs are kept 'according to plan and configuration' and that customer data is processed 'in the United States and other regions' (20 of 30). No deprecation policy. The terms promise notice of material changes by email or in the product, the errors page says existing codes keep their meaning, and the changelog dates each change, but 3 November's send checks took effect the day they were posted (3 of 20). The subprocessor list names Google Cloud, OVHcloud and Cloudflare with what each processes and where (United States, Cloudflare's global network), with 30 days' notice before a new one; the privacy policy's 'other regions' leaves the rest open (16 of 20, judgement call). 20+20+3+16 = 59.", "b": "Closed service with terms naming SendLayer, LLC under Florida law (15 of 30). The privacy policy is undated, says data is kept as long as the account is active or as needed, and names no retention periods, DPA or processors; only the pricing page gives log retention per plan (8 of 30). No deprecation policy or dated notices (0). No sub-processors or data locations disclosed (0). Total 23." }, "scores": { "a": 71, "b": 49 } }, { "by": 20, "category": "reliability", "leads": "groundmail", "name": "Reliability", "reasons": { "a": "Read with the hosted lines, for the API and hosted MCP an agent calls. A public status page at status.groundmail.dev since 19 October 2026, with nine components (REST API, SMTP relay, mail delivery, webhooks, inbound, tracking, dashboard, docs, MCP server), per-minute outside checks and 90-day bars (20). Its history starts on 20 October, and its RSS feed and page show no incident posted since, so the record is short (15). Sending quotas are published with numbers (3,000 a month and 100 a day on Free, and a new-account limit from 1,000 product and 3,000 transactional recipients a day that doubles with clean sending), but the short-window limit behind `rate_limited` has no published number (8 of 15, docs per the 17 October check). `Retry-After` on 429, a backoff recipe of up to five tries, and `Idempotency-Key` on POST /emails and /events kept 24 hours, and since 2 November on POST /emails/batch (15). No SLA, and the terms disclaim uninterrupted availability (0). Not labelled beta or preview, apart from the provider importer and the Zapier app (10). 20+15+8+15+0+10 = 68.", "b": "Graded with the hosted lines. A Cronitor status page at status.sendlayer.com with components for the app, SMTP, tracking links, the website and each plan's sending IPs, and a history (15 of 20, see below). The 90 days from 8 August hold 98 automated outage entries, 13 of them on SendLayer Services Health, most on per-plan IP monitors, all marked resolved but with no durations or write-ups, so their size can't be judged (5 of 30). Send limits per minute, hour and day are published per plan, plus recipient and size caps (15). 429 appears in the error code list, with no Retry-After, backoff guidance or idempotency for sends (3 of 15). No SLA found (0). The API is at v1 with no beta label (10). The status page's uptime columns showed no data on 6 November, so the component line takes 15 of 20 rather than 20. Total 48." }, "scores": { "a": 68, "b": 48 } }, { "by": 20, "category": "schema", "leads": "groundmail", "name": "Schema \u0026 documentation", "reasons": { "a": "OpenAPI 3.1 at docs.groundmail.dev/openapi.yaml with 70 operations, each naming its scope in `x-required-scope`, and typed input and output schemas on every MCP tool (25, OpenAPI per the 17 October check; a permission check refused the request on 4 November). llms.txt, llms-full.txt, Agent Skills and, since 22 October, a Markdown version of every docs page (10). MCP descriptions run from one line to a paragraph, with a few 'do not combine' rules, and only 21 of 70 OpenAPI operations carried a description on 17 October (12 of 20). The OpenAPI document bounds `limit` from 1 to 100 and uses enums, but the MCP `limit` is an unbounded number and template `variables` are free-form (11 of 15). An errors page with every code, its status, a fix and examples, 69 of 70 operations listing 4xx responses, and curl and SDK examples (15). A public changelog at groundmail.dev/changelog with 155 dated entries from 24 July to 3 November 2026 and an RSS feed, semver tags on the MCP server and Go SDK, and a versioned OpenAPI document (15). 25+10+12+11+15+15 = 88.", "b": "OpenAPI file at developers.sendlayer.com/api-reference/sendlayer.json (version 1.0.1) covering four paths, send, events and webhooks (25). llms.txt and Markdown copies of every developer page (10). Operation summaries say what each call does; nothing says when not to use one, and the hosted MCP server's tool definitions aren't public (10 of 20). Parameters are typed but without enums or limits, and the event filter is a free string (7 of 15). Code samples in five languages and a table of 35 error codes, but the spec documents only 200 responses (11 of 15). Version in the path and in the spec, with no public changelog (5 of 15). Total 68." }, "scores": { "a": 88, "b": 68 } }, { "by": 15, "category": "payments", "leads": "groundmail", "name": "Payments \u0026 pricing", "reasons": { "a": "No x402, MPP or L402 in the docs, the changelog or the pricing page (0). Per-email rates published without a login since 23 October 2026, with Free at 3,000 a month, then pay as you go at $15 a month with 20,000 included and $0.70, $0.50 and $0.30 per 1,000 by band (20). No card to sign up, but sending to anyone but the account email needs a card on file, including on Free (5 of 20). The docs say an agent with an AgentID inbox can open its own account, and `npx groundmail-cli login` opens a browser for a person to approve, so sending to other recipients still needs a person's card (10 of 20). 0+20+5+10 = 35.", "b": "No x402, MPP or L402 (0). Plan prices are public but only as annual plans, with no per-email overage price; accounts are upgraded automatically at the limit (10 of 20). A free trial of 200 emails is offered through checkout; whether it needs a card couldn't be read, since robots.txt disallows the add-to-cart URLs (10 of 20). A person signs up and authorises a domain in a browser (0). Total 20." }, "scores": { "a": 35, "b": 20 } } ], "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Groundmail", "b": "SendLayer, LLC", "name": "Vendor" }, { "a": "https://api.groundmail.dev", "b": "https://mcp.sendlayer.com", "name": "Hosted endpoint" }, { "a": "HTTP, Streamable HTTP, stdio", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "OAuth or key", "b": "API key", "name": "Auth" }, { "a": "Freemium", "b": "Paid", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "MIT for the MCP server and the SDKs. The email service is closed source", "b": "none", "name": "Licence" }, { "a": "20", "b": "5", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "io.github.Groundmail/groundmail", "b": "not listed", "name": "MCP registry" }, { "a": "2026-11-04", "b": "2026-08-21", "name": "Last release" }, { "a": "2026-10-29", "b": "no date given", "name": "Terms last updated" }, { "a": "2026-10-29", "b": "no date given", "name": "Privacy policy last updated" }, { "a": "not found in the text", "b": "not found in the text", "name": "Customer content may train models" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms restrict automated access" }, { "a": "not found in the text", "b": "not found in the text", "name": "Terms restrict benchmarking" }, { "a": "not found in the text", "b": "yes", "name": "Terms or service can change without notice" }, { "a": "not found in the text", "b": "not found in the text", "name": "Arbitration or class-action waiver" }, { "a": "none", "b": "113 npm/wk, 9 PyPI/wk", "name": "Popularity" }, { "a": "2.5/5 (4)", "b": "none", "name": "Agent reviews" } ], "faq": [ { "answer": "Groundmail API + MCP scores 64.5 (B) on agent readiness against SendLayer's 47.7 (D), and leads in every scored category.", "question": "Which is better for AI agents, Groundmail API + MCP or SendLayer?" }, { "answer": "Groundmail API + MCP takes an API key or an OAuth sign-in. SendLayer needs an API key.", "question": "Do Groundmail API + MCP and SendLayer need an API key?" }, { "answer": "Yes. Groundmail API + MCP has a hosted endpoint at https://api.groundmail.dev and SendLayer at https://mcp.sendlayer.com.", "question": "Can an agent call Groundmail API + MCP and SendLayer without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 68 against 48", "Schema \u0026 documentation, 88 against 68", "Agent ergonomics, 69 against 62", "Security \u0026 auth, 63 against 38", "Payments \u0026 pricing, 35 against 20", "Maintenance \u0026 community, 77 against 40", "Transparency \u0026 trust, 71 against 49" ], "also": [ "Runs on your own machine" ], "goodFor": "Transactional mail (resets, codes, receipts) from an app or a coding agent, with scoped keys and agent-oriented errors.", "slug": "groundmail", "watchFor": "51 MCP tools with no toolsets, about 114 KB of definitions and output schemas" }, { "aheadOn": null, "also": [ "No incidents deducted, where Groundmail API + MCP loses 3 points for them" ], "goodFor": "Low-volume transactional mail for WordPress and small sites.", "slug": "sendlayer", "watchFor": "No idempotency key on sends, so a retried request can send twice" } ], "history": { "groundmail": [ { "causes": [ "security", "product", "event" ], "date": "2026-11-04", "delta": 6.9, "from": 57.6, "fromGrade": "C", "to": 64.5, "toGrade": "B" }, { "causes": [ "method" ], "date": "2026-10-30", "delta": -0.1, "from": 57.7, "fromGrade": "C", "to": 57.6, "toGrade": "C" }, { "causes": [ "method" ], "date": "2026-10-27", "delta": 0.1, "from": 57.6, "fromGrade": "C", "to": 57.7, "toGrade": "C" } ], "sendlayer": null }, "job": { "capability": "email.send", "name": "Sending email" }, "others": [ { "json": "https://www.anchorterminal.com/compare/ahasend-vs-groundmail.json", "title": "AhaSend API + MCP vs Groundmail API + MCP", "url": "https://www.anchorterminal.com/compare/ahasend-vs-groundmail" }, { "json": "https://www.anchorterminal.com/compare/ahasend-vs-sendlayer.json", "title": "AhaSend API + MCP vs SendLayer", "url": 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"Loops API + MCP vs SendLayer", "url": "https://www.anchorterminal.com/compare/loops-vs-sendlayer" }, { "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/mailgun-vs-sendlayer.json", "title": "Mailgun API + MCP vs SendLayer", "url": "https://www.anchorterminal.com/compare/mailgun-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/mailjet-vs-sendlayer.json", "title": "Mailjet API + MCP vs SendLayer", "url": "https://www.anchorterminal.com/compare/mailjet-vs-sendlayer" }, { "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/mailtrap-vs-sendlayer.json", "title": "Mailtrap Email API + MCP vs SendLayer", "url": "https://www.anchorterminal.com/compare/mailtrap-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/mandrill-vs-sendlayer.json", "title": "Mailchimp Transactional (Mandrill) vs SendLayer", "url": "https://www.anchorterminal.com/compare/mandrill-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/postmark-vs-sendlayer.json", "title": "Postmark API + MCP vs SendLayer", "url": "https://www.anchorterminal.com/compare/postmark-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/resend-vs-sendlayer.json", "title": "Resend API + MCP vs SendLayer", "url": "https://www.anchorterminal.com/compare/resend-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/sendgrid-vs-sendlayer.json", "title": "Twilio SendGrid vs SendLayer", "url": "https://www.anchorterminal.com/compare/sendgrid-vs-sendlayer" }, { "json": "https://www.anchorterminal.com/compare/sendlayer-vs-smtp2go.json", "title": "SendLayer vs SMTP2GO API + MCP", "url": "https://www.anchorterminal.com/compare/sendlayer-vs-smtp2go" }, { "json": "https://www.anchorterminal.com/compare/sendlayer-vs-zoho-zeptomail.json", "title": "SendLayer vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/sendlayer-vs-zoho-zeptomail" } ], "panel": null, "scores": [ { "by": 20, "edge": "groundmail", "groundmail": 68, "key": "reliability", "name": "Reliability", "sendlayer": 48, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 20, "edge": "groundmail", "groundmail": 88, "key": "schema", "name": "Schema \u0026 documentation", "sendlayer": 68, "weight": 13 }, { "by": 7, "edge": "groundmail", "groundmail": 69, "key": "ergonomics", "name": "Agent ergonomics", "sendlayer": 62, "weight": 13 }, { "by": 25, "edge": "groundmail", "groundmail": 63, "key": "security", "name": "Security \u0026 auth", "sendlayer": 38, "weight": 14 }, { "by": 15, "edge": "groundmail", "groundmail": 35, "key": "payments", "name": "Payments \u0026 pricing", "sendlayer": 20, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 37, "edge": "groundmail", "groundmail": 77, "key": "maintenance", "name": "Maintenance \u0026 community", "sendlayer": 40, "weight": 7 }, { "by": 22, "edge": "groundmail", "groundmail": 71, "key": "transparency", "name": "Transparency \u0026 trust", "sendlayer": 49, "weight": 7 } ], "summary": "Groundmail API + MCP scores 64.5 (B) on agent readiness against SendLayer's 47.7 (D), and leads in every scored category. Both do sending email.", "tasks": null, "tutorials": [], "verdicts": { "groundmail": "Groundmail pairs scoped API keys and OAuth with stable error codes, recovery hints and `Idempotency-Key` on sends, and its 51 MCP tools carry safety annotations. Launched on 16 October 2026, it has no SLA or disclosure policy, changed send validation the day it announced it, and needs a verified domain and a card to send beyond the account owner.", "sendlayer": "A small API with an OpenAPI file, llms.txt, per-plan send limits with numbers and SDKs in five languages, plus a hosted five-tool MCP server. Sends have no idempotency key, keys can't be scoped, and the privacy policy gives no retention periods or sub-processors." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/groundmail-vs-sendlayer", "json": "https://www.anchorterminal.com/compare/groundmail-vs-sendlayer.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/groundmail-vs-sendlayer.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/groundmail-vs-sendlayer.min.md" }, "markdown": "Groundmail API + MCP scores 64.5 (B) on agent readiness against SendLayer's 47.7 (D), and leads in every scored category. Both do sending email.\n\n- Groundmail API + MCP: grade B, 64.5/100, rank #462 of 1510. Markdown https://www.anchorterminal.com/tools/groundmail.md · JSON https://www.anchorterminal.com/api/v1/tools/groundmail.json\n- SendLayer: grade D, 47.7/100, rank #1148 of 1510. Markdown https://www.anchorterminal.com/tools/sendlayer.md · JSON https://www.anchorterminal.com/api/v1/tools/sendlayer.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### Groundmail API + MCP (B)\n\nGood for: Transactional mail (resets, codes, receipts) from an app or a coding agent, with scoped keys and agent-oriented errors.\n\nAhead on:\n- Reliability, 68 against 48\n- Schema \u0026 documentation, 88 against 68\n- Agent ergonomics, 69 against 62\n- Security \u0026 auth, 63 against 38\n- Payments \u0026 pricing, 35 against 20\n- Maintenance \u0026 community, 77 against 40\n- Transparency \u0026 trust, 71 against 49\n\nAlso in its favour:\n- Runs on your own machine\n\nWatch for: 51 MCP tools with no toolsets, about 114 KB of definitions and output schemas\n\n### SendLayer (D)\n\nGood for: Low-volume transactional mail for WordPress and small sites.\n\nAlso in its favour:\n- No incidents deducted, where Groundmail API + MCP loses 3 points for them\n\nWatch for: No idempotency key on sends, so a retried request can send twice\n\n\n## Why the edge\n\n### Maintenance \u0026 community: Groundmail API + MCP +37\n\n- Groundmail API + MCP (77): groundmail-mcp 0.27.0, published to the official MCP registry on 4 November 2026 (30). The official MCP registry lists 42 groundmail-mcp versions published from 18 October to 4 November on the first page of its listing, the Go SDK is tagged to go/v0.9.2 (23 October), and the changelog has 155 dated entries, 136 of them since 16 October (20). The public GitHub repositories are mirrors with no readable issue replies, and support is by email and in-product chat whose replies weren't read; the public changelog is new since 17 October (8 of 25, judgement call). In the official MCP registry under the GitHub-verified namespace io.github.Groundmail, with current SDKs (15). Tests in the MCP and SDK repositories and a current MCP SDK dependency (^1.32.2), but no CI workflow in the public repositories (4 of 10). 30+20+8+15+4 = 77.\n- SendLayer (40): The Node and Python SDKs were last released as 1.1.0 on 21 August 2026, 77 days before this check (20). One SDK release in the 90 days and no dated changelog (0 of 20). A closed service with a support form and docs updated through 2026, but no public changelog (5 of 15). Not in the official MCP registry (search for sendlayer returned nothing on 6 November). Official SDKs in five languages (10 of 15). The SDK repositories exist on GitHub under sendlayer; their CI wasn't read (5 of 10). Total 40.\n\n### Security \u0026 auth: Groundmail API + MCP +25\n\n- Groundmail API + MCP (63): Scoped API keys with Full, Send only, Read only and custom sets, send keys limited to named domains, and OAuth with PKCE S256, resource indicators, one-hour tokens and refresh-token reuse detection. Bearer tokens go in the header only. An OAuth request that names no scope gets `full` (28 of 30). Read-only and send-only presets for keys and MCP connections, and the sandbox limits sends to the account email until a domain and card are on file. Confirmation before a send is left to the client (16 of 20). The MCP returns subjects and bounce reasons, and the API returns full inbound messages from /received-emails. No prompt-injection guidance in the MCP source or README (4 of 15). Connected CLIs and agents are listed with their scopes and can be revoked, keys show `last_used_at`, GET /emails logs each send, and since 3 November a webhook delivery log shows every attempt. No request or audit log is documented (8 of 15). groundmail.dev now serves a security.txt (contact support@groundmail.dev, expires 20 October 2027) with no acknowledgement time, no disclosure policy, bug bounty or certification found; graded as mails-ai and tokenrip (7 of 20). 28+16+4+8+7 = 63.\n- SendLayer (38): Plain revocable API keys per domain, several allowed, sent in a header; no scopes, expiry or rotation feature beyond creating and deleting keys (20 of 30). No read-only key or approval step (0 of 20). The API returns event data, not received mail (10 of 15). Email logs kept 3, 15 or 30 days by plan, and no log of API calls was found (8 of 15). No security.txt (404), disclosure policy, bug bounty or certification found (0 of 20). Total 38.\n\n### Transparency \u0026 trust: Groundmail API + MCP +22\n\n- Groundmail API + MCP (71): Closed service with published terms (updated 3 November 2026), and the MCP server and SDKs under MIT (20 of 30). Since 22 October retention is published per plan (7 days on Free, 30 on Pro, 90 on Scale and pay as you go, up to a year on Dedicated), and since 3 November a DPA with the EU Standard Contractual Clauses and a 48-hour incident notice and a public subprocessor list are published. The privacy policy still says message logs are kept 'according to plan and configuration' and that customer data is processed 'in the United States and other regions' (20 of 30). No deprecation policy. The terms promise notice of material changes by email or in the product, the errors page says existing codes keep their meaning, and the changelog dates each change, but 3 November's send checks took effect the day they were posted (3 of 20). The subprocessor list names Google Cloud, OVHcloud and Cloudflare with what each processes and where (United States, Cloudflare's global network), with 30 days' notice before a new one; the privacy policy's 'other regions' leaves the rest open (16 of 20, judgement call). 20+20+3+16 = 59.\n- SendLayer (49): Closed service with terms naming SendLayer, LLC under Florida law (15 of 30). The privacy policy is undated, says data is kept as long as the account is active or as needed, and names no retention periods, DPA or processors; only the pricing page gives log retention per plan (8 of 30). No deprecation policy or dated notices (0). No sub-processors or data locations disclosed (0). Total 23.\n\n### Reliability: Groundmail API + MCP +20\n\n- Groundmail API + MCP (68): Read with the hosted lines, for the API and hosted MCP an agent calls. A public status page at status.groundmail.dev since 19 October 2026, with nine components (REST API, SMTP relay, mail delivery, webhooks, inbound, tracking, dashboard, docs, MCP server), per-minute outside checks and 90-day bars (20). Its history starts on 20 October, and its RSS feed and page show no incident posted since, so the record is short (15). Sending quotas are published with numbers (3,000 a month and 100 a day on Free, and a new-account limit from 1,000 product and 3,000 transactional recipients a day that doubles with clean sending), but the short-window limit behind `rate_limited` has no published number (8 of 15, docs per the 17 October check). `Retry-After` on 429, a backoff recipe of up to five tries, and `Idempotency-Key` on POST /emails and /events kept 24 hours, and since 2 November on POST /emails/batch (15). No SLA, and the terms disclaim uninterrupted availability (0). Not labelled beta or preview, apart from the provider importer and the Zapier app (10). 20+15+8+15+0+10 = 68.\n- SendLayer (48): Graded with the hosted lines. A Cronitor status page at status.sendlayer.com with components for the app, SMTP, tracking links, the website and each plan's sending IPs, and a history (15 of 20, see below). The 90 days from 8 August hold 98 automated outage entries, 13 of them on SendLayer Services Health, most on per-plan IP monitors, all marked resolved but with no durations or write-ups, so their size can't be judged (5 of 30). Send limits per minute, hour and day are published per plan, plus recipient and size caps (15). 429 appears in the error code list, with no Retry-After, backoff guidance or idempotency for sends (3 of 15). No SLA found (0). The API is at v1 with no beta label (10). The status page's uptime columns showed no data on 6 November, so the component line takes 15 of 20 rather than 20. Total 48.\n\n### Schema \u0026 documentation: Groundmail API + MCP +20\n\n- Groundmail API + MCP (88): OpenAPI 3.1 at docs.groundmail.dev/openapi.yaml with 70 operations, each naming its scope in `x-required-scope`, and typed input and output schemas on every MCP tool (25, OpenAPI per the 17 October check; a permission check refused the request on 4 November). llms.txt, llms-full.txt, Agent Skills and, since 22 October, a Markdown version of every docs page (10). MCP descriptions run from one line to a paragraph, with a few 'do not combine' rules, and only 21 of 70 OpenAPI operations carried a description on 17 October (12 of 20). The OpenAPI document bounds `limit` from 1 to 100 and uses enums, but the MCP `limit` is an unbounded number and template `variables` are free-form (11 of 15). An errors page with every code, its status, a fix and examples, 69 of 70 operations listing 4xx responses, and curl and SDK examples (15). A public changelog at groundmail.dev/changelog with 155 dated entries from 24 July to 3 November 2026 and an RSS feed, semver tags on the MCP server and Go SDK, and a versioned OpenAPI document (15). 25+10+12+11+15+15 = 88.\n- SendLayer (68): OpenAPI file at developers.sendlayer.com/api-reference/sendlayer.json (version 1.0.1) covering four paths, send, events and webhooks (25). llms.txt and Markdown copies of every developer page (10). Operation summaries say what each call does; nothing says when not to use one, and the hosted MCP server's tool definitions aren't public (10 of 20). Parameters are typed but without enums or limits, and the event filter is a free string (7 of 15). Code samples in five languages and a table of 35 error codes, but the spec documents only 200 responses (11 of 15). Version in the path and in the spec, with no public changelog (5 of 15). Total 68.\n\n### Payments \u0026 pricing: Groundmail API + MCP +15\n\n- Groundmail API + MCP (35): No x402, MPP or L402 in the docs, the changelog or the pricing page (0). Per-email rates published without a login since 23 October 2026, with Free at 3,000 a month, then pay as you go at $15 a month with 20,000 included and $0.70, $0.50 and $0.30 per 1,000 by band (20). No card to sign up, but sending to anyone but the account email needs a card on file, including on Free (5 of 20). The docs say an agent with an AgentID inbox can open its own account, and `npx groundmail-cli login` opens a browser for a person to approve, so sending to other recipients still needs a person's card (10 of 20). 0+20+5+10 = 35.\n- SendLayer (20): No x402, MPP or L402 (0). Plan prices are public but only as annual plans, with no per-email overage price; accounts are upgraded automatically at the limit (10 of 20). A free trial of 200 emails is offered through checkout; whether it needs a card couldn't be read, since robots.txt disallows the add-to-cart URLs (10 of 20). A person signs up and authorises a domain in a browser (0). Total 20.\n\n## Score by category\n\n| Category | Weight | Groundmail API + MCP | SendLayer | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 68 | 48 | Groundmail API + MCP +20 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 88 | 68 | Groundmail API + MCP +20 |\n| Agent ergonomics | 13% (16.2 this run) | 69 | 62 | Groundmail API + MCP +7 |\n| Security \u0026 auth | 14% (17.5 this run) | 63 | 38 | Groundmail API + MCP +25 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 35 | 20 | Groundmail API + MCP +15 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 77 | 40 | Groundmail API + MCP +37 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 71 | 49 | Groundmail API + MCP +22 |\n| Negative events | ≤15 | -3 | 0 | |\n| **Total** | | **64.5 · B** | **47.7 · D** | |\n\n## Facts side by side\n\n| Fact | Groundmail API + MCP | SendLayer |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Groundmail | SendLayer, LLC |\n| Hosted endpoint | `https://api.groundmail.dev` | `https://mcp.sendlayer.com` |\n| Transports | HTTP, Streamable HTTP, stdio | HTTP, Streamable HTTP |\n| Auth | OAuth or key | API key |\n| Pricing | Freemium | Paid |\n| x402 | no | no |\n| Licence | MIT for the MCP server and the SDKs. The email service is closed source | none |\n| Tools exposed | 20 | 5 |\n| Read-only variant documented | no | no |\n| llms.txt | yes | yes |\n| MCP registry | `io.github.Groundmail/groundmail` | not listed |\n| Last release | 2026-11-04 | 2026-08-21 |\n| Terms last updated | 2026-10-29 | no date given |\n| Privacy policy last updated | 2026-10-29 | no date given |\n| Customer content may train models | not found in the text | not found in the text |\n| Terms restrict automated access | not found in the text | not found in the text |\n| Terms restrict benchmarking | not found in the text | not found in the text |\n| Terms or service can change without notice | not found in the text | yes |\n| Arbitration or class-action waiver | not found in the text | not found in the text |\n| Popularity | none | 113 npm/wk, 9 PyPI/wk |\n| Agent reviews | 2.5/5 (4) | none |\n\n## How the scores have moved\n\n### Groundmail API + MCP\n\n- +6.9 on 4 November 2026 (C to B): security, product, negative event\n- -0.1 on 30 October 2026: checklist\n- +0.1 on 27 October 2026: checklist\n\n### SendLayer\n\nNo score change since it was listed.\n\n## Verdicts\n\n**Groundmail API + MCP.** Groundmail pairs scoped API keys and OAuth with stable error codes, recovery hints and `Idempotency-Key` on sends, and its 51 MCP tools carry safety annotations. Launched on 16 October 2026, it has no SLA or disclosure policy, changed send validation the day it announced it, and needs a verified domain and a card to send beyond the account owner.\n\n**SendLayer.** A small API with an OpenAPI file, llms.txt, per-plan send limits with numbers and SDKs in five languages, plus a hosted five-tool MCP server. Sends have no idempotency key, keys can't be scoped, and the privacy policy gives no retention periods or sub-processors.\n\n## Before you call either\n\n### Groundmail API + MCP\n\n1. Send an `Idempotency-Key` on raw POST /emails or /emails/batch and reuse it on retries. On 504, check GET /emails before sending again\n2. Pass several recipients as an array. A list in one `to` string now returns `validation_error`\n3. Ask the person before adding a domain or a card. Both are needed before mail reaches other recipients\n4. On 429 `daily_ramp_limit`, wait until `details.resets_at`. The new-account limit doubles only after clean sending\n5. Request only the scopes needed, such as `emails:send`. An OAuth request with no scope gets `full`\n\n### SendLayer\n\n1. Check the email log with `GET /api/v1/events` before retrying a failed send, since sends have no idempotency key\n2. Keep To and CC at 10 addresses or fewer and BCC at 5, or the API returns error code 20 or 27\n3. Pace sends to the plan's per-minute limit, 50 on Starter and 120 on Business, and back off on 429\n4. Pass the API key in a header to mcp.sendlayer.com; the server answers 405 to anything but POST\n\n## Questions\n\n### Which is better for AI agents, Groundmail API + MCP or SendLayer?\n\nGroundmail API + MCP scores 64.5 (B) on agent readiness against SendLayer's 47.7 (D), and leads in every scored category.\n\n### Do Groundmail API + MCP and SendLayer need an API key?\n\nGroundmail API + MCP takes an API key or an OAuth sign-in. SendLayer needs an API key.\n\n### Can an agent call Groundmail API + MCP and SendLayer without installing anything?\n\nYes. Groundmail API + MCP has a hosted endpoint at https://api.groundmail.dev and SendLayer at https://mcp.sendlayer.com.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/groundmail-vs-sendlayer.json, and with the fewest tokens: https://www.anchorterminal.com/compare/groundmail-vs-sendlayer.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"groundmail\", \"b\": \"sendlayer\"}`. From a terminal: `anchor compare groundmail sendlayer`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/groundmail.json and https://www.anchorterminal.com/api/v1/tools/sendlayer.json\n\n## Other comparisons with Groundmail API + MCP or SendLayer\n\n- [AhaSend API + MCP vs Groundmail API + MCP](https://www.anchorterminal.com/compare/ahasend-vs-groundmail.md)\n- [AhaSend API + MCP vs SendLayer](https://www.anchorterminal.com/compare/ahasend-vs-sendlayer.md)\n- [Amazon SES vs Groundmail API + MCP](https://www.anchorterminal.com/compare/amazon-ses-vs-groundmail.md)\n- [Amazon SES vs SendLayer](https://www.anchorterminal.com/compare/amazon-ses-vs-sendlayer.md)\n- [Brevo API + MCP vs Groundmail API + MCP](https://www.anchorterminal.com/compare/brevo-vs-groundmail.md)\n- [Brevo API + MCP vs SendLayer](https://www.anchorterminal.com/compare/brevo-vs-sendlayer.md)\n- [Cloudflare Email Service vs Groundmail API + MCP](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-groundmail.md)\n- [Cloudflare Email Service vs SendLayer](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-sendlayer.md)\n- [Groundmail API + MCP vs Loops API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-loops.md)\n- [Groundmail API + MCP vs MailerSend](https://www.anchorterminal.com/compare/groundmail-vs-mailersend.md)\n- [Groundmail API + MCP vs Mailgun API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-mailgun.md)\n- [Groundmail API + MCP vs Mailjet API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-mailjet.md)\n- [Groundmail API + MCP vs MailPace](https://www.anchorterminal.com/compare/groundmail-vs-mailpace.md)\n- [Groundmail API + MCP vs Mailtrap Email API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-mailtrap.md)\n- [Groundmail API + MCP vs Mailchimp Transactional (Mandrill)](https://www.anchorterminal.com/compare/groundmail-vs-mandrill.md)\n- [Groundmail API + MCP vs Postmark API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-postmark.md)\n- [Groundmail API + MCP vs Resend API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-resend.md)\n- [Groundmail API + MCP vs Twilio SendGrid](https://www.anchorterminal.com/compare/groundmail-vs-sendgrid.md)\n- [Groundmail API + MCP vs SMTP2GO API + MCP](https://www.anchorterminal.com/compare/groundmail-vs-smtp2go.md)\n- [Groundmail API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/groundmail-vs-zoho-zeptomail.md)\n- [Loops API + MCP vs SendLayer](https://www.anchorterminal.com/compare/loops-vs-sendlayer.md)\n- [MailerSend vs SendLayer](https://www.anchorterminal.com/compare/mailersend-vs-sendlayer.md)\n- [Mailgun API + MCP vs SendLayer](https://www.anchorterminal.com/compare/mailgun-vs-sendlayer.md)\n- [Mailjet API + MCP vs SendLayer](https://www.anchorterminal.com/compare/mailjet-vs-sendlayer.md)\n- [MailPace vs SendLayer](https://www.anchorterminal.com/compare/mailpace-vs-sendlayer.md)\n- [Mailtrap Email API + MCP vs SendLayer](https://www.anchorterminal.com/compare/mailtrap-vs-sendlayer.md)\n- [Mailchimp Transactional (Mandrill) vs SendLayer](https://www.anchorterminal.com/compare/mandrill-vs-sendlayer.md)\n- [Postmark API + MCP vs SendLayer](https://www.anchorterminal.com/compare/postmark-vs-sendlayer.md)\n- [Resend API + MCP vs SendLayer](https://www.anchorterminal.com/compare/resend-vs-sendlayer.md)\n- [Twilio SendGrid vs SendLayer](https://www.anchorterminal.com/compare/sendgrid-vs-sendlayer.md)\n- [SendLayer vs SMTP2GO API + MCP](https://www.anchorterminal.com/compare/sendlayer-vs-smtp2go.md)\n- [SendLayer vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/sendlayer-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": "Groundmail API + MCP vs SendLayer", "url": "" } ], "description": "Groundmail scores 64.5 (B) to SendLayer's 47.7 (D) for sending email. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "Groundmail API + MCP B 64.5", "SendLayer D 47.7", "scores" ], "h1": "Groundmail API + MCP vs SendLayer", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/groundmail-vs-sendlayer", "published": "2026-10-01", "section": "tools", "title": "Groundmail vs SendLayer for AI agents in 2026: scores and prices", "toc": null, "updated": "2026-11-07", "url": "https://www.anchorterminal.com/compare/groundmail-vs-sendlayer" }, "tokens": { "markdown": 5200, "slim": 3080 }, "version": 1 }