{ "data": { "a": { "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" } }, "answer": "MailPace and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 58.4 (C) and 58.2 (C). Zoho CPaaS (formerly ZeptoMail) leads on schema \u0026 documentation, security \u0026 auth, payments \u0026 pricing and transparency \u0026 trust.", "b": { "slug": "zoho-zeptomail", "name": "Zoho CPaaS (formerly ZeptoMail)", "vendor": "Zoho Corporation", "vendorUrl": "https://www.zoho.com/cpaas/", "kind": "http-api", "category": "email", "summary": "Transactional email service from Zoho, renamed from ZeptoMail to Zoho CPaaS in September 2026. It sends application email through a REST API or SMTP relay, with templates, domain management, suppression lists, logs and webhooks.", "url": "https://www.anchorterminal.com/tools/zoho-zeptomail", "markdownUrl": "https://www.anchorterminal.com/tools/zoho-zeptomail.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/zoho-zeptomail.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/zoho-zeptomail.json", "dns": "zoho-zeptomail.grade.anchorterminal.com", "license": "Proprietary service under the Zoho CPaaS terms of use. The Node SDK on npm is MIT", "transports": [ "http" ], "remoteUrl": "https://cpaas.zoho.com/v1.1", "packages": [ { "registry": "npm", "name": "zeptomail" } ], "auth": "mixed", "authNotes": "Sending takes a send key in the `Authorization` header with the prefix Zoho-enczapikey. Each Agent has its own keys, one set per channel, copied from the console's SMTP/API tab or created and deleted by API. Logs, domains, templates, agents and suppression lists take a Zoho OAuth 2.0 access token (authorisation code grant, one-hour tokens, refresh tokens) with per-resource scopes. Access is self-serve, but every new account passes a manual review that the docs say takes two business days.", "pricing": "usage", "pricingNotes": "Prepaid email credits of 10,000 emails each, valid six months and counted per recipient, with the first credit free and no monthly plan. A sandbox Agent accepts 10,000 test emails a day without sending them. Credits can be bought only after the account review. A dedicated IP is priced by the month, billed annually. The amounts are filled in by script from a data file and weren't read (https://www.zoho.com/cpaas/pricing.md, checked 2026-11-02).", "priceSummary": "Pay per use", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the API docs, the OpenAPI file or the pricing page (checked 2026-10-08).", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": null, "npmWeekly": 40110, "pypiWeekly": null, "asOf": "2026-10-08" }, "docsUrl": "https://www.zoho.com/cpaas/help/api/api-home.html", "llmsTxt": "https://www.zoho.com/cpaas/llms.txt", "openapi": "https://www.zohowebstatic.com/sites/zweb/json/api/cpaas/oas.json", "capabilities": [ "email.send", "email.templates", "email.domains", "email.analytics" ], "tags": [ "hosted", "usage", "openapi", "llms-txt", "oauth", "smtp", "webhooks", "sandbox", "typescript", "status-page", "bug-bounty", "soc2" ], "lastRelease": "2026-09-28", "graded": true, "anchor": { "graded": true, "score": 58.2, "grade": "C", "agentReady": false, "rank": 759, "ranked": true, "rankOf": 1510, "categoryRank": 18, "methodology": "0.7", "run": "2026-10-01", "scores": { "ergonomics": 55, "maintenance": 44, "payments": 30, "reliability": 41, "schema": 78, "security": 78, "transparency": 82 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-11-02" }, "negative": 0, "verdict": "A public OpenAPI 3.0 file covers all 42 operations, each Agent has its own send-only key, and email is prepaid per 10,000 with the first credit free. No API rate limit, 429 handling, idempotency key or SLA was found in the reviewed documentation, and new accounts wait for a manual review.", "bestFor": "Low-volume transactional senders who want prepaid credits without a monthly plan, and teams already on Zoho.", "strengths": [ "Public OpenAPI 3.0.3 file with 42 operations, plus llms.txt and a Markdown copy of every help page", "Send keys are per Agent and per channel and can only send. Management calls use OAuth with READ, CREATE, UPDATE and DELETE scopes per resource", "Prepaid email credits of 10,000 emails, valid six months, with the first credit free and no monthly plan", "IP allow lists for sending, the REST API and the web console, and activity logs kept for one year", "The terms commit to a six-month deprecation period for a retired API version" ], "weaknesses": [ "No API rate limit, 429 behaviour or Retry-After was found in the reviewed documentation or the OpenAPI file", "No idempotency key on send. `client_reference` is a tracking label only", "Every new account is reviewed by Zoho staff, which the docs say takes two business days, before credits can be bought", "The only official SDK found is the Node package, last published on 29 May 2026 and still named zeptomail", "The OAuth guide puts the client secret and refresh token in the token URL's query string", "No inbound email, and no SLA was found" ], "agentNotes": [ "Call the base URL for the account's region (cpaas.zoho.com, .eu, .in, .com.au, .jp or .com.cn). A key from one region fails on another", "Send with `Authorization: Zoho-enczapikey \u003ckey\u003e`. Logs, domains, templates, agents and suppressions need a Zoho OAuth token as `Authorization: Zoho-oauthtoken \u003ctoken\u003e`", "Post OAuth client secrets and refresh tokens in the request body, not the query string the guide shows, so they stay out of logs", "Don't retry a timed-out send blindly. There is no idempotency key, so look the message up by `client_reference` in the email logs first", "Count one email per recipient, including cc and bcc, and keep each address field to 500 entries and each attachment to 15 MB", "Use a sandbox Agent for tests. It accepts up to 10,000 emails a day and sends none of them" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 4, "avgRating": 2.8, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.7", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 58.2 } ], "editorialScores": { "ergonomics": 55, "maintenance": 44, "payments": 30, "reliability": 41, "schema": 78, "security": 78, "transparency": 69 }, "provenanceScore": 94, "checked": { "categories": { "ergonomics": "2026-11-02", "maintenance": "2026-11-02", "payments": "2026-11-02", "reliability": "2026-11-02", "schema": "2026-11-02", "security": "2026-11-02", "transparency": "2026-11-02" }, "last": "2026-11-02", "lastMoved": "2026-11-02", "oldest": "2026-11-02", "stale": false, "staleAfterDays": 90 } }, "connect": { "install": "npm install zeptomail", "http": "curl --request POST --url https://cpaas.zoho.com/v1.1/email \\\n --header 'Authorization: Zoho-enczapikey REPLACE_WITH_YOUR_KEY' \\\n --header 'content-type: application/json' \\\n --data '{\"from\":{\"address\":\"hello@yourapp.com\",\"name\":\"Your App\"},\"to\":[{\"email_address\":{\"address\":\"user@example.com\",\"name\":\"User\"}}],\"subject\":\"Test Email\",\"htmlbody\":\"\u003cp\u003eTest email sent successfully.\u003c/p\u003e\"}'" }, "letme": { "capability": "https://letme.dev/email.send", "tool": "https://letme.dev/zoho-zeptomail" }, "sameCompany": [ "zoho-books", "zoho-crm", "zoho-desk", "zoho-recruit", "zoho-people", "zoho-mail" ], "area": "communication", "provenance": { "legalEntity": "Zoho Corporation", "domain": "zoho.com", "domainRegistered": "2004-01-16", "endpointOnVendorDomain": true, "terms": "https://www.zoho.com/cpaas/terms.html", "privacy": "https://www.zoho.com/privacy.html", "statusPage": "https://us.zohostatus.com/", "changelog": "https://www.zoho.com/cpaas/whats-new.html", "securityTxt": "valid", "checked": "2026-11-02", "notes": [ "The Zoho CPaaS terms of use name the contracting party as the Zoho entity for the customer's region. That is Zoho Corporation for the United States and Zoho Corporation Private Limited for India (https://www.zoho.com/legal/zoho-contracting-entities.html).", "The privacy field points at Zoho's privacy policy, last updated 22 December 2025, whose Part II covers the data customers process through Zoho services. Zoho CPaaS has no privacy policy of its own.", "status.zoho.com redirects to us.zohostatus.com, which lists Zepto Mail, Zepto Mail-SMTP and Zepto Mail-SMTP (PORT:465) under the old name. Other regions have their own status sites.", "www.zoho.com/.well-known/security.txt names security@zohocorp.com and the bug bounty, and expires on 30 June 2028. cpaas.zoho.com/.well-known/security.txt returns 403.", "RDAP for zoho.com gives a registration date of 2004-01-16.", "On 2 November 2026 us.zohostatus.com answered robots.txt with a 404 carrying an error page, read as blocked, so the status page wasn't re-read." ], "score": 94 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/zoho-zeptomail.json", "live": { "slug": "zoho-zeptomail", "probe": { "target": "https://cpaas.zoho.com/v1.1", "method": "get", "lastAt": "2026-11-07T19:22:46.889478517Z", "lastOk": true, "lastStatus": 403, "lastMs": 461, "lastNote": "asks for credentials", "authRequired": true, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 444, "p95ms24h": 557, "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": 247 }, { "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": 250, "ok": 250 }, { "date": "2026-10-29", "probes": 249, "ok": 249 }, { "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 } ] }, "vendorStatus": { "page": "https://us.zohostatus.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-11-07T04:49:02.430674227Z" }, "versions": [ { "registry": "npm", "name": "zeptomail", "version": "8.0.1", "seenAt": "2026-11-07T00:19:26.142653107Z" } ], "npmWeekly": 35781, "securityTxt": { "url": "https://zoho.com/.well-known/security.txt", "state": "valid", "expires": "2028-06-30T23:59:59.000Z", "checkedAt": "2026-11-07T15:59:50.941776064Z" }, "llmsTxt": { "url": "https://www.zoho.com/cpaas/llms.txt", "ok": true, "status": 200, "checkedAt": "2026-11-07T15:34:35.165808162Z" }, "domain": { "domain": "zoho.com", "registered": "2004-01-16", "source": "https://rdap.verisign.com/com/v1/domain/zoho.com", "checkedAt": "2026-11-01T14:25:40.832306171Z" }, "pages": [ { "url": "https://www.zoho.com/cpaas/whats-new.html", "kind": "deprecations", "status": 304, "checkedAt": "2026-11-07T14:38:01.103447641Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "7bf282bb5347" }, { "url": "https://www.zoho.com/cpaas/pricing.html", "kind": "pricing", "status": 304, "checkedAt": "2026-11-02T07:40:16.034374166Z", "changedAt": "2026-10-21T01:09:06.032033866Z", "fingerprint": "f1f3ee5174e9" }, { "url": "https://www.zoho.com/cpaas/pricing.md", "kind": "pricing", "status": 304, "checkedAt": "2026-11-07T14:37:55.988830385Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "948a5178ba37" }, { "url": "https://www.zoho.com/cpaas/terms.html", "kind": "terms", "status": 304, "checkedAt": "2026-11-07T14:37:56.039176711Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "a4fd5ba82732" } ], "updatedAt": "2026-11-07T19:22:46.889478517Z" } }, "edges": [ { "by": 29, "category": "reliability", "leads": "mailpace", "name": "Reliability", "reasons": { "a": "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.", "b": "Graded on the hosted email API with the hosted lines. Zoho's status site at us.zohostatus.com listed three Zepto Mail components with status and incident history sections on 8 October, and status.zoho.com points there; the line is kept as for zoho-desk and zoho-crm (20). On 2 November the host answered robots.txt with a 404 carrying an error page (\"We have encountered a problem while executing your request\"), read as blocked as for the other Zoho listings, so nothing else was requested. The 8 October RSS reading (last status change 29 July 2026) is struck, and no history in the window was read (5). No request rate limit was found. The docs give payload caps (500 addresses a field, 60 attachments, 15 MB each), a per-day sending limit error (SMI_115) and the sandbox allowance of 10,000 emails a day (6). No 429 handling, Retry-After or idempotency key found in the docs or the error-code table (0). No SLA found (0). The email channel is generally available, while SMS, WhatsApp and voice are marked beta (10)." }, "scores": { "a": 70, "b": 41 } }, { "by": 28, "category": "security", "leads": "zoho-zeptomail", "name": "Security \u0026 auth", "reasons": { "a": "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.", "b": "Send keys are per Agent and per channel, can be created, listed and deleted by API, and can only send and upload attachments. Management calls use Zoho OAuth 2.0 with READ, CREATE, UPDATE and DELETE scopes per resource and one-hour access tokens. That earns 30, less 10 because the OAuth guide documents the client secret and refresh token in the token URL's query string (20). Read-only scopes, send-only keys, sandbox Agents and IP allow lists for sending, the REST API and the web console. No approval step for deletes (15). No inbound mail, so responses hold only the account's own logs and settings (10). Activity logs per user kept one year with export, and email logs for 60 days that show the triggering IP (13). security.txt valid until 30 June 2028 naming security@zohocorp.com and Zoho's bug bounty, and SOC 2 Type II and ISO/IEC 27001 on Zoho's compliance page, the same evidence zoho-crm, zoho-desk and zoho-books score 20 on. The 2 points held back on 8 October for no advisory feed aren't a checklist condition the other Zoho listings apply (20)." }, "scores": { "a": 50, "b": 78 } }, { "by": 24, "category": "schema", "leads": "zoho-zeptomail", "name": "Schema \u0026 documentation", "reasons": { "a": "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.", "b": "One public OpenAPI 3.0.3 file with 42 operations, linked from the docs without a login (25). llms.txt at zoho.com/cpaas/llms.txt and a second for the help centre, with a Markdown copy of each page (10). Every operation has a description, most of them one sentence, with nothing on when not to use it (10). Request bodies name required fields and length caps, with 9 enums across the file, but log filters take dates as free strings and responses are typed as a bare JSON object (10). Sample requests and responses on every page and an error-code table of 24 rows with remedies. The 401 body we got from the live endpoint has a different shape from the documented sample (11). Version 1.1 in the path and a What's New page dated by month only (12). The OpenAPI file was not re-read on 2 November (a permission check refused the request); the line rests on the 8 October reading." }, "scores": { "a": 54, "b": 78 } }, { "by": 21, "category": "maintenance", "leads": "mailpace", "name": "Maintenance \u0026 community", "reasons": { "a": "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.", "b": "Every dated source found was checked. What's New dates entries by month and has nothing after September 2026 (the rename with SMS, WhatsApp and voice endpoints), which lies 33 to 63 days back, and month-only entries don't set recency inside the month. The official WordPress plugin (transmail on wordpress.org, by Zoho Mail) was last updated on 28 September 2026 at 3.3.4, 35 days back. The API help pages carry no dates. The getting-started and subscription help pages say \"Last updated: October 22, 2026\", but a revised help page shows no API change, so the stamp doesn't set recency (omnisend's reading, where a new operation did); counted, recency would be 30 and maintenance 54. So the last change is within 90 days, not shown within 30 (20, cause time). In the 90 days from 4 August, What's New has one entry for September and one for August (28 of whose 31 days fall inside), and the plugin's 3.3.4 counts half as a package release that doesn't change the service. The July entries have left the window. 2.5 is fewer than three (0, cause time). A public changelog, a support address and a contact page that says support runs around the clock. We saw no public forum replies (10). The Node SDK zeptomail 8.0.1 of 29 May 2026 per the 8 October check (npm not re-read), the only official SDK found (10). The npm package names no source repository, so CI and dependency health couldn't be read (4). 20 + 0 + 10 + 10 + 4 = 44." }, "scores": { "a": 65, "b": 44 } }, { "by": 16, "category": "ergonomics", "leads": "mailpace", "name": "Agent ergonomics", "reasons": { "a": "Responses are small, the send returns an id and status and Email Status returns one email (18 of 25). Only the domains list takes `limit`, `offset`, `sort` and `direction`; there is no endpoint to list or search sent mail (8 of 20). Errors are JSON with a human message and an HTTP status for each case in the documented table, with no stable error codes (14 of 20). `Idempotency-Key` on sends, kept 24 hours per token, and failed validations are not stored so they can be retried. The MCP server marks send as not idempotent and revoke as destructive (18 of 20). A send needs from, to, a subject and a body; official libraries for Node, Rails, Go and PHP transports and an SMTP route (13 of 15). Total 71.", "b": "Send responses are small, and the logs endpoint takes offset and limit, with no field selection (15). Thirteen filters on email logs, among them recipient, subject, date range, `client_reference` and bounce or delivery state (16). Errors carry a code, a sub-code and a message, and the docs pair each with a fix (16). No idempotency key and no guidance on retrying a send (0). A send needs only from, to and subject. The one official SDK found is for Node, and managing the account needs a second credential type (8)." }, "scores": { "a": 71, "b": 55 } }, { "by": 7, "category": "transparency", "leads": "zoho-zeptomail", "name": "Transparency \u0026 trust", "reasons": { "a": "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.", "b": "Closed service with its own published terms of use, and an MIT Node SDK (20). Zoho's privacy policy of 22 December 2025 covers service data, and the CPaaS pages say content is stored only on opt-in for 60 days and logs for 60 days. The pages disagree on deletion. The GDPR page says account data is deleted within 24 hours of a 48-hour grace period, the privacy policy says a clean-up every six months with backups three months later, and the April 2026 changelog entry says content can be kept up to 50 days (18). The terms commit to a six-month deprecation period after a service announcement, with no dated notices to check it against (16). Six data centre regions are named with their hosts, and Zoho publishes a sub-processor directory by service that loads by script and that we couldn't read (15)." }, "scores": { "a": 75, "b": 82 } } ], "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "OhMySMTP Ltd", "b": "Zoho Corporation", "name": "Vendor" }, { "a": "no (local only)", "b": "https://cpaas.zoho.com/v1.1", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP", "name": "Transports" }, { "a": "API key", "b": "OAuth or key", "name": "Auth" }, { "a": "Paid", "b": "Pay per use", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "none", "b": "Proprietary service under the Zoho CPaaS terms of use. The Node SDK on npm is MIT", "name": "Licence" }, { "a": "12", "b": "none", "name": "Tools exposed" }, { "a": "no", "b": "no", "name": "Read-only variant documented" }, { "a": "no", "b": "yes", "name": "llms.txt" }, { "a": "2026-10-22", "b": "2026-09-28", "name": "Last release" }, { "a": "2026-01-09", "b": "no date given", "name": "Terms last updated" }, { "a": "2026-08-30", "b": "2025-12-22", "name": "Privacy policy last updated" }, { "a": "not found in the text", "b": "yes", "name": "Customer content may train models" }, { "a": "yes", "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": "not found in the text", "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": "1 stars, 207 npm/wk", "b": "40k npm/wk", "name": "Popularity" }, { "a": "none", "b": "2.8/5 (4)", "name": "Agent reviews" } ], "faq": [ { "answer": "MailPace and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 58.4 (C) and 58.2 (C). Zoho CPaaS (formerly ZeptoMail) leads on schema \u0026 documentation, security \u0026 auth, payments \u0026 pricing and transparency \u0026 trust.", "question": "Which is better for AI agents, MailPace or Zoho CPaaS (formerly ZeptoMail)?" }, { "answer": "MailPace needs an API key. Zoho CPaaS (formerly ZeptoMail) takes an API key or an OAuth sign-in.", "question": "Do MailPace and Zoho CPaaS (formerly ZeptoMail) need an API key?" }, { "answer": "No hosted endpoint is listed for MailPace. Zoho CPaaS (formerly ZeptoMail) has a hosted endpoint at https://cpaas.zoho.com/v1.1.", "question": "Can an agent call MailPace and Zoho CPaaS (formerly ZeptoMail) without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 70 against 41", "Agent ergonomics, 71 against 55", "Maintenance \u0026 community, 65 against 44" ], "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" }, { "aheadOn": [ "Schema \u0026 documentation, 78 against 54", "Security \u0026 auth, 78 against 50", "Payments \u0026 pricing, 30 against 25", "Transparency \u0026 trust, 82 against 75" ], "also": [ "A hosted endpoint, with nothing to install" ], "goodFor": "Low-volume transactional senders who want prepaid credits without a monthly plan, and teams already on Zoho.", "slug": "zoho-zeptomail", "watchFor": "No API rate limit, 429 behaviour or Retry-After was found in the reviewed documentation or the OpenAPI file" } ], "history": { "mailpace": null, "zoho-zeptomail": [ { "causes": [ "correction", "time" ], "date": "2026-11-02", "delta": -3.6, "from": 61.8, "fromGrade": "C", "to": 58.2, "toGrade": "C" } ] }, "job": { "capability": "email.send", "name": "Sending email" }, "others": [ { "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/ahasend-vs-zoho-zeptomail.json", "title": "AhaSend API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/ahasend-vs-zoho-zeptomail" }, { "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/amazon-ses-vs-zoho-zeptomail.json", "title": "Amazon SES vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/amazon-ses-vs-zoho-zeptomail" }, { "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/brevo-vs-zoho-zeptomail.json", "title": "Brevo API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/brevo-vs-zoho-zeptomail" }, { "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/cloudflare-email-service-vs-zoho-zeptomail.json", "title": "Cloudflare Email Service vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/cloudflare-email-service-vs-zoho-zeptomail" }, { "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/groundmail-vs-zoho-zeptomail.json", "title": "Groundmail API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/groundmail-vs-zoho-zeptomail" }, { "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/loops-vs-zoho-zeptomail.json", "title": "Loops API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/loops-vs-zoho-zeptomail" }, { "json": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace.json", "title": "MailerSend vs MailPace", "url": "https://www.anchorterminal.com/compare/mailersend-vs-mailpace" }, { "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/mailgun-vs-zoho-zeptomail.json", "title": "Mailgun API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/mailgun-vs-zoho-zeptomail" }, { "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/mailjet-vs-zoho-zeptomail.json", "title": "Mailjet API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/mailjet-vs-zoho-zeptomail" }, { "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/mailtrap-vs-zoho-zeptomail.json", "title": "Mailtrap Email API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/mailtrap-vs-zoho-zeptomail" }, { "json": "https://www.anchorterminal.com/compare/mandrill-vs-zoho-zeptomail.json", "title": "Mailchimp Transactional (Mandrill) vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/mandrill-vs-zoho-zeptomail" }, { "json": "https://www.anchorterminal.com/compare/postmark-vs-zoho-zeptomail.json", "title": "Postmark API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/postmark-vs-zoho-zeptomail" }, { "json": "https://www.anchorterminal.com/compare/resend-vs-zoho-zeptomail.json", "title": "Resend API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/resend-vs-zoho-zeptomail" }, { "json": "https://www.anchorterminal.com/compare/sendgrid-vs-zoho-zeptomail.json", "title": "Twilio SendGrid vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/sendgrid-vs-zoho-zeptomail" }, { "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" }, { "json": "https://www.anchorterminal.com/compare/smtp2go-vs-zoho-zeptomail.json", "title": "SMTP2GO API + MCP vs Zoho CPaaS (formerly ZeptoMail)", "url": "https://www.anchorterminal.com/compare/smtp2go-vs-zoho-zeptomail" } ], "panel": null, "scores": [ { "by": 29, "edge": "mailpace", "key": "reliability", "mailpace": 70, "name": "Reliability", "weight": 16, "zoho-zeptomail": 41 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 24, "edge": "zoho-zeptomail", "key": "schema", "mailpace": 54, "name": "Schema \u0026 documentation", "weight": 13, "zoho-zeptomail": 78 }, { "by": 16, "edge": "mailpace", "key": "ergonomics", "mailpace": 71, "name": "Agent ergonomics", "weight": 13, "zoho-zeptomail": 55 }, { "by": 28, "edge": "zoho-zeptomail", "key": "security", "mailpace": 50, "name": "Security \u0026 auth", "weight": 14, "zoho-zeptomail": 78 }, { "by": 5, "edge": "zoho-zeptomail", "key": "payments", "mailpace": 25, "name": "Payments \u0026 pricing", "weight": 10, "zoho-zeptomail": 30 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 21, "edge": "mailpace", "key": "maintenance", "mailpace": 65, "name": "Maintenance \u0026 community", "weight": 7, "zoho-zeptomail": 44 }, { "by": 7, "edge": "zoho-zeptomail", "key": "transparency", "mailpace": 75, "name": "Transparency \u0026 trust", "weight": 7, "zoho-zeptomail": 82 } ], "summary": "MailPace and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 58.4 (C) and 58.2 (C). Zoho CPaaS (formerly ZeptoMail) leads on schema \u0026 documentation, security \u0026 auth, payments \u0026 pricing and transparency \u0026 trust. Both do sending email.", "tasks": null, "tutorials": [], "verdicts": { "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.", "zoho-zeptomail": "A public OpenAPI 3.0 file covers all 42 operations, each Agent has its own send-only key, and email is prepaid per 10,000 with the first credit free. No API rate limit, 429 handling, idempotency key or SLA was found in the reviewed documentation, and new accounts wait for a manual review." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail", "json": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.md", "mcp": "https://www.anchorterminal.com/mcp", "slim": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.min.md" }, "markdown": "MailPace and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 58.4 (C) and 58.2 (C). Zoho CPaaS (formerly ZeptoMail) leads on schema \u0026 documentation, security \u0026 auth, payments \u0026 pricing and transparency \u0026 trust. Both do sending email.\n\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- Zoho CPaaS (formerly ZeptoMail): grade C, 58.2/100, rank #759 of 1510. Markdown https://www.anchorterminal.com/tools/zoho-zeptomail.md · JSON https://www.anchorterminal.com/api/v1/tools/zoho-zeptomail.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### MailPace (C)\n\nGood for: Low-volume transactional mail from EU-hosted infrastructure with idempotent sends and no tracking.\n\nAhead on:\n- Reliability, 70 against 41\n- Agent ergonomics, 71 against 55\n- Maintenance \u0026 community, 65 against 44\n\nWatch for: No OpenAPI spec, llms.txt or Markdown docs for agents; the reference is Docusaurus pages\n\n### Zoho CPaaS (formerly ZeptoMail) (C)\n\nGood for: Low-volume transactional senders who want prepaid credits without a monthly plan, and teams already on Zoho.\n\nAhead on:\n- Schema \u0026 documentation, 78 against 54\n- Security \u0026 auth, 78 against 50\n- Payments \u0026 pricing, 30 against 25\n- Transparency \u0026 trust, 82 against 75\n\nAlso in its favour:\n- A hosted endpoint, with nothing to install\n\nWatch for: No API rate limit, 429 behaviour or Retry-After was found in the reviewed documentation or the OpenAPI file\n\n\n## Why the edge\n\n### Reliability: MailPace +29\n\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- Zoho CPaaS (formerly ZeptoMail) (41): Graded on the hosted email API with the hosted lines. Zoho's status site at us.zohostatus.com listed three Zepto Mail components with status and incident history sections on 8 October, and status.zoho.com points there; the line is kept as for zoho-desk and zoho-crm (20). On 2 November the host answered robots.txt with a 404 carrying an error page (\"We have encountered a problem while executing your request\"), read as blocked as for the other Zoho listings, so nothing else was requested. The 8 October RSS reading (last status change 29 July 2026) is struck, and no history in the window was read (5). No request rate limit was found. The docs give payload caps (500 addresses a field, 60 attachments, 15 MB each), a per-day sending limit error (SMI_115) and the sandbox allowance of 10,000 emails a day (6). No 429 handling, Retry-After or idempotency key found in the docs or the error-code table (0). No SLA found (0). The email channel is generally available, while SMS, WhatsApp and voice are marked beta (10).\n\n### Security \u0026 auth: Zoho CPaaS (formerly ZeptoMail) +28\n\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- Zoho CPaaS (formerly ZeptoMail) (78): Send keys are per Agent and per channel, can be created, listed and deleted by API, and can only send and upload attachments. Management calls use Zoho OAuth 2.0 with READ, CREATE, UPDATE and DELETE scopes per resource and one-hour access tokens. That earns 30, less 10 because the OAuth guide documents the client secret and refresh token in the token URL's query string (20). Read-only scopes, send-only keys, sandbox Agents and IP allow lists for sending, the REST API and the web console. No approval step for deletes (15). No inbound mail, so responses hold only the account's own logs and settings (10). Activity logs per user kept one year with export, and email logs for 60 days that show the triggering IP (13). security.txt valid until 30 June 2028 naming security@zohocorp.com and Zoho's bug bounty, and SOC 2 Type II and ISO/IEC 27001 on Zoho's compliance page, the same evidence zoho-crm, zoho-desk and zoho-books score 20 on. The 2 points held back on 8 October for no advisory feed aren't a checklist condition the other Zoho listings apply (20).\n\n### Schema \u0026 documentation: Zoho CPaaS (formerly ZeptoMail) +24\n\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- Zoho CPaaS (formerly ZeptoMail) (78): One public OpenAPI 3.0.3 file with 42 operations, linked from the docs without a login (25). llms.txt at zoho.com/cpaas/llms.txt and a second for the help centre, with a Markdown copy of each page (10). Every operation has a description, most of them one sentence, with nothing on when not to use it (10). Request bodies name required fields and length caps, with 9 enums across the file, but log filters take dates as free strings and responses are typed as a bare JSON object (10). Sample requests and responses on every page and an error-code table of 24 rows with remedies. The 401 body we got from the live endpoint has a different shape from the documented sample (11). Version 1.1 in the path and a What's New page dated by month only (12). The OpenAPI file was not re-read on 2 November (a permission check refused the request); the line rests on the 8 October reading.\n\n### Maintenance \u0026 community: MailPace +21\n\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- Zoho CPaaS (formerly ZeptoMail) (44): Every dated source found was checked. What's New dates entries by month and has nothing after September 2026 (the rename with SMS, WhatsApp and voice endpoints), which lies 33 to 63 days back, and month-only entries don't set recency inside the month. The official WordPress plugin (transmail on wordpress.org, by Zoho Mail) was last updated on 28 September 2026 at 3.3.4, 35 days back. The API help pages carry no dates. The getting-started and subscription help pages say \"Last updated: October 22, 2026\", but a revised help page shows no API change, so the stamp doesn't set recency (omnisend's reading, where a new operation did); counted, recency would be 30 and maintenance 54. So the last change is within 90 days, not shown within 30 (20, cause time). In the 90 days from 4 August, What's New has one entry for September and one for August (28 of whose 31 days fall inside), and the plugin's 3.3.4 counts half as a package release that doesn't change the service. The July entries have left the window. 2.5 is fewer than three (0, cause time). A public changelog, a support address and a contact page that says support runs around the clock. We saw no public forum replies (10). The Node SDK zeptomail 8.0.1 of 29 May 2026 per the 8 October check (npm not re-read), the only official SDK found (10). The npm package names no source repository, so CI and dependency health couldn't be read (4). 20 + 0 + 10 + 10 + 4 = 44.\n\n### Agent ergonomics: MailPace +16\n\n- MailPace (71): Responses are small, the send returns an id and status and Email Status returns one email (18 of 25). Only the domains list takes `limit`, `offset`, `sort` and `direction`; there is no endpoint to list or search sent mail (8 of 20). Errors are JSON with a human message and an HTTP status for each case in the documented table, with no stable error codes (14 of 20). `Idempotency-Key` on sends, kept 24 hours per token, and failed validations are not stored so they can be retried. The MCP server marks send as not idempotent and revoke as destructive (18 of 20). A send needs from, to, a subject and a body; official libraries for Node, Rails, Go and PHP transports and an SMTP route (13 of 15). Total 71.\n- Zoho CPaaS (formerly ZeptoMail) (55): Send responses are small, and the logs endpoint takes offset and limit, with no field selection (15). Thirteen filters on email logs, among them recipient, subject, date range, `client_reference` and bounce or delivery state (16). Errors carry a code, a sub-code and a message, and the docs pair each with a fix (16). No idempotency key and no guidance on retrying a send (0). A send needs only from, to and subject. The one official SDK found is for Node, and managing the account needs a second credential type (8).\n\n### Transparency \u0026 trust: Zoho CPaaS (formerly ZeptoMail) +7\n\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- Zoho CPaaS (formerly ZeptoMail) (82): Closed service with its own published terms of use, and an MIT Node SDK (20). Zoho's privacy policy of 22 December 2025 covers service data, and the CPaaS pages say content is stored only on opt-in for 60 days and logs for 60 days. The pages disagree on deletion. The GDPR page says account data is deleted within 24 hours of a 48-hour grace period, the privacy policy says a clean-up every six months with backups three months later, and the April 2026 changelog entry says content can be kept up to 50 days (18). The terms commit to a six-month deprecation period after a service announcement, with no dated notices to check it against (16). Six data centre regions are named with their hosts, and Zoho publishes a sub-processor directory by service that loads by script and that we couldn't read (15).\n\n## Score by category\n\n| Category | Weight | MailPace | Zoho CPaaS (formerly ZeptoMail) | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 70 | 41 | MailPace +29 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 54 | 78 | Zoho CPaaS (formerly ZeptoMail) +24 |\n| Agent ergonomics | 13% (16.2 this run) | 71 | 55 | MailPace +16 |\n| Security \u0026 auth | 14% (17.5 this run) | 50 | 78 | Zoho CPaaS (formerly ZeptoMail) +28 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 25 | 30 | Zoho CPaaS (formerly ZeptoMail) +5 |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 65 | 44 | MailPace +21 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 75 | 82 | Zoho CPaaS (formerly ZeptoMail) +7 |\n| Negative events | ≤15 | 0 | 0 | |\n| **Total** | | **58.4 · C** | **58.2 · C** | |\n\n## Facts side by side\n\n| Fact | MailPace | Zoho CPaaS (formerly ZeptoMail) |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | OhMySMTP Ltd | Zoho Corporation |\n| Hosted endpoint | no (local only) | `https://cpaas.zoho.com/v1.1` |\n| Transports | HTTP | HTTP |\n| Auth | API key | OAuth or key |\n| Pricing | Paid | Pay per use |\n| x402 | no | no |\n| Licence | none | Proprietary service under the Zoho CPaaS terms of use. The Node SDK on npm is MIT |\n| Tools exposed | 12 | none |\n| Read-only variant documented | no | no |\n| llms.txt | no | yes |\n| Last release | 2026-10-22 | 2026-09-28 |\n| Terms last updated | 2026-01-09 | no date given |\n| Privacy policy last updated | 2026-08-30 | 2025-12-22 |\n| Customer content may train models | not found in the text | yes |\n| Terms restrict automated access | yes | 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 | not found in the text |\n| Arbitration or class-action waiver | not found in the text | not found in the text |\n| Popularity | 1 stars, 207 npm/wk | 40k npm/wk |\n| Agent reviews | none | 2.8/5 (4) |\n\n## How the scores have moved\n\n### MailPace\n\nNo score change since it was listed.\n\n### Zoho CPaaS (formerly ZeptoMail)\n\n- -3.6 on 2 November 2026: correction, time\n\n## Verdicts\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**Zoho CPaaS (formerly ZeptoMail).** A public OpenAPI 3.0 file covers all 42 operations, each Agent has its own send-only key, and email is prepaid per 10,000 with the first credit free. No API rate limit, 429 handling, idempotency key or SLA was found in the reviewed documentation, and new accounts wait for a manual review.\n\n## Before you call either\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### Zoho CPaaS (formerly ZeptoMail)\n\n1. Call the base URL for the account's region (cpaas.zoho.com, .eu, .in, .com.au, .jp or .com.cn). A key from one region fails on another\n2. Send with `Authorization: Zoho-enczapikey \u003ckey\u003e`. Logs, domains, templates, agents and suppressions need a Zoho OAuth token as `Authorization: Zoho-oauthtoken \u003ctoken\u003e`\n3. Post OAuth client secrets and refresh tokens in the request body, not the query string the guide shows, so they stay out of logs\n4. Don't retry a timed-out send blindly. There is no idempotency key, so look the message up by `client_reference` in the email logs first\n5. Count one email per recipient, including cc and bcc, and keep each address field to 500 entries and each attachment to 15 MB\n6. Use a sandbox Agent for tests. It accepts up to 10,000 emails a day and sends none of them\n\n## Questions\n\n### Which is better for AI agents, MailPace or Zoho CPaaS (formerly ZeptoMail)?\n\nMailPace and Zoho CPaaS (formerly ZeptoMail) score within a point of each other on agent readiness, 58.4 (C) and 58.2 (C). Zoho CPaaS (formerly ZeptoMail) leads on schema \u0026 documentation, security \u0026 auth, payments \u0026 pricing and transparency \u0026 trust.\n\n### Do MailPace and Zoho CPaaS (formerly ZeptoMail) need an API key?\n\nMailPace needs an API key. Zoho CPaaS (formerly ZeptoMail) takes an API key or an OAuth sign-in.\n\n### Can an agent call MailPace and Zoho CPaaS (formerly ZeptoMail) without installing anything?\n\nNo hosted endpoint is listed for MailPace. Zoho CPaaS (formerly ZeptoMail) has a hosted endpoint at https://cpaas.zoho.com/v1.1.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.json, and with the fewest tokens: https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"mailpace\", \"b\": \"zoho-zeptomail\"}`. From a terminal: `anchor compare mailpace zoho-zeptomail`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/mailpace.json and https://www.anchorterminal.com/api/v1/tools/zoho-zeptomail.json\n\n## Other comparisons with MailPace or Zoho CPaaS (formerly ZeptoMail)\n\n- [AhaSend API + MCP vs MailPace](https://www.anchorterminal.com/compare/ahasend-vs-mailpace.md)\n- [AhaSend API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/ahasend-vs-zoho-zeptomail.md)\n- [Amazon SES vs MailPace](https://www.anchorterminal.com/compare/amazon-ses-vs-mailpace.md)\n- [Amazon SES vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/amazon-ses-vs-zoho-zeptomail.md)\n- [Brevo API + MCP vs MailPace](https://www.anchorterminal.com/compare/brevo-vs-mailpace.md)\n- [Brevo API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/brevo-vs-zoho-zeptomail.md)\n- [Cloudflare Email Service vs MailPace](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-mailpace.md)\n- [Cloudflare Email Service vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/cloudflare-email-service-vs-zoho-zeptomail.md)\n- [Groundmail API + MCP vs MailPace](https://www.anchorterminal.com/compare/groundmail-vs-mailpace.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 MailPace](https://www.anchorterminal.com/compare/loops-vs-mailpace.md)\n- [Loops API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/loops-vs-zoho-zeptomail.md)\n- [MailerSend vs MailPace](https://www.anchorterminal.com/compare/mailersend-vs-mailpace.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- [Mailgun API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mailgun-vs-zoho-zeptomail.md)\n- [Mailjet API + MCP vs MailPace](https://www.anchorterminal.com/compare/mailjet-vs-mailpace.md)\n- [Mailjet API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mailjet-vs-zoho-zeptomail.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- [Mailtrap Email API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mailtrap-vs-zoho-zeptomail.md)\n- [Mailchimp Transactional (Mandrill) vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/mandrill-vs-zoho-zeptomail.md)\n- [Postmark API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/postmark-vs-zoho-zeptomail.md)\n- [Resend API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/resend-vs-zoho-zeptomail.md)\n- [Twilio SendGrid vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/sendgrid-vs-zoho-zeptomail.md)\n- [SendLayer vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/sendlayer-vs-zoho-zeptomail.md)\n- [SMTP2GO API + MCP vs Zoho CPaaS (formerly ZeptoMail)](https://www.anchorterminal.com/compare/smtp2go-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": "MailPace vs Zoho CPaaS (formerly ZeptoMail)", "url": "" } ], "description": "MailPace and Zoho CPaaS score within a point of each other for sending email, 58.4 and 58.2 out of 100. Prices, MCP, x402, uptime and agent notes side by side.", "facts": [ "MailPace C 58.4", "Zoho CPaaS (formerly ZeptoMail) C 58.2", "scores" ], "h1": "MailPace vs Zoho CPaaS (formerly ZeptoMail)", "image": "https://www.anchorterminal.com/assets/og/default.png", "path": "/compare/mailpace-vs-zoho-zeptomail", "published": "2026-10-01", "section": "tools", "title": "MailPace vs Zoho CPaaS for AI agents in 2026: scores and prices", "toc": null, "updated": "2026-11-07", "url": "https://www.anchorterminal.com/compare/mailpace-vs-zoho-zeptomail" }, "tokens": { "markdown": 5800, "slim": 3530 }, "version": 1 }