{ "data": { "a": { "slug": "emailengine", "name": "EmailEngine", "vendor": "Postal Systems OÜ", "vendorUrl": "https://emailengine.app", "kind": "http-api", "category": "mailbox-access", "summary": "EmailEngine is self-hosted software from Postal Systems that puts one REST API over Gmail, Microsoft 365 and IMAP mailboxes, with webhooks for new mail and a beta MCP server. The owner runs it with Redis.", "url": "https://www.anchorterminal.com/tools/emailengine", "markdownUrl": "https://www.anchorterminal.com/tools/emailengine.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/emailengine.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/emailengine.json", "repo": "https://github.com/postalsys/emailengine", "license": "Source available under the EmailEngine licence agreement, version 2.1 of 17 October 2023. Not open source. The PHP SDK is MIT", "transports": [ "http" ], "packages": [ { "registry": "npm", "name": "emailengine-app" }, { "registry": "oci", "name": "postalsys/emailengine" }, { "registry": "packagist", "name": "postalsys/emailengine-php" } ], "auth": "api-key", "authNotes": "Access is granted by whoever runs the instance, with no vendor approval or app review. Every request takes a 64-character token as `Authorization: Bearer`, or in the `access_token` query parameter. Tokens are created in the admin interface, with the CLI (`emailengine tokens issue`) or through POST /v1/tokens, which only mints tokens bound to one account or narrowed by a permissions record. A token carries scopes (`*`, api, metrics, smtp, imap-proxy, mcp, mcp-manage), an optional account binding, allowlists of actions (read, write, send, destructive) and groups, an IP allowlist, an expiry and a rate limit. The beta MCP endpoint also has an optional built-in OAuth 2.1 server. Mailboxes are connected with the operator's own Google and Microsoft OAuth2 apps, service accounts or IMAP passwords, which stay inside the instance.", "pricing": "paid", "pricingNotes": "$1,450 or EUR 1,200 a year, excluding VAT, for unlimited mailboxes, instances and API calls, bought with an account at postalsys.com. Every install can start a 14-day trial with full functionality from its own dashboard, with no sign-up and no card, so an agent's owner can start without a contract. When the trial ends the instance stops processing accounts until a licence key is added. A perpetual licence is sold through sales with no public price. The owner also pays for the server and Redis (https://emailengine.app/, https://postalsys.com/plans, checked 2026-10-08).", "priceSummary": "$120.83 / mo", "where": "local", "x402": { "level": "no", "evidence": "No x402, MPP or L402 on emailengine.app, in the documentation or in the OpenAPI spec (checked 2026-10-08). Licences are bought by card at postalsys.com, with Stripe named as the payment processor.", "endpoints": [] }, "toolCount": null, "popularity": { "githubStars": 2237, "npmWeekly": 388, "pypiWeekly": null, "asOf": "2026-10-08" }, "docsUrl": "https://learn.emailengine.app/", "llmsTxt": "https://emailengine.app/llms.txt", "openapi": "https://go.emailengine.app/swagger.json", "capabilities": [ "mailbox.read", "mailbox.search", "mailbox.send", "mailbox.drafts", "mailbox.sync" ], "tags": [ "self-hosted", "source-available", "paid", "trial", "api-key", "openapi", "llms-txt", "mcp", "webhooks", "imap", "gmail", "microsoft-365", "docker", "nodejs", "php" ], "lastRelease": "2026-10-05", "graded": true, "anchor": { "graded": true, "score": 71.4, "grade": "BB", "agentReady": true, "rank": 106, "ranked": true, "rankOf": 629, "categoryRank": 3, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 80, "maintenance": 81, "payments": 40, "reliability": 79, "schema": 91, "security": 71, "transparency": 72 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-08" }, "negative": -3, "negativeNotes": [ "27 September 2026. Version 2.81.2, a patch release, removed the `bounces` field from the message list, message details and messageNew payloads, listed under bug fixes with no earlier notice found in the changelog. The bounce still arrives through the messageBounce webhook, and the entry is documented, so the smallest deduction applies (https://github.com/postalsys/emailengine/blob/master/CHANGELOG.md)" ], "verdict": "A self-hosted REST API over Gmail, Microsoft 365 and IMAP, with a public OpenAPI 3.0 spec and tokens that can be bound to one account, limited by action and group, and rate limited. It needs a server, Redis and a $1,450 yearly licence after a 14-day trial, and the MCP endpoint is a beta, off by default.", "bestFor": "A team that must keep mailbox access on its own infrastructure, has many mailboxes across Gmail, Microsoft 365 and IMAP, and can run a server and Redis.", "strengths": [ "Public OpenAPI 3.0 spec for version 2.82.2 with 82 operations, plus llms.txt on both sites and a capabilities.json manifest", "Tokens can be bound to one account, narrowed by action and group, limited by IP range, expiry and rate, and are stored only as SHA-256 hashes", "Idempotency-Key header on both send routes, and 429 responses carry Retry-After and a ttl field", "Ten tagged releases between 7 September and 5 October 2026, and the last eight test runs on master passed", "Written prompt-injection guidance, with MCP mail access set to none by default and message bodies returned as sanitised HTML" ], "weaknesses": [ "Not open source. Running it beyond the 14-day trial needs a subscription at $1,450 or EUR 1,200 a year", "The owner has to run a server and Redis. There is no hosted service, status page or SLA", "The MCP endpoint is labelled beta, is off by default, and its tool set may change between releases", "A token may also travel in the `access_token` query parameter, and API authentication can be switched off in settings", "Version 2.81.2, a patch release, removed the `bounces` field from message responses, and 2.82.0 removed the Document Store in a minor release", "One maintainer, no guaranteed support response time, and issues are disabled on the GitHub repository per the GitHub API" ], "agentNotes": [ "Ask the operator for a token bound to one account with a permissions record. Mint more with POST /v1/tokens, which refuses instance-wide tokens without one", "Send the token in the Authorization header, not the `access_token` query parameter, so it stays out of proxy logs", "Page with `cursor` from `nextPageCursor`. `page` works only on IMAP accounts, and search covers one folder unless `path` is `\\All` on Gmail or Microsoft Graph", "Set an Idempotency-Key header on POST /v1/account/{account}/submit. A 2xx means queued, so follow the result through the outbox or the messageSent and messageFailed webhooks", "Treat message text as untrusted. For MCP, the operator must enable the endpoint first and mail access starts at none" ], "metrics": { "kind": "local", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "BB", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 71.4 } ], "editorialScores": { "ergonomics": 80, "maintenance": 81, "payments": 40, "reliability": 79, "schema": 91, "security": 71, "transparency": 68 }, "provenanceScore": 76 }, "connect": { "install": "curl -LO https://go.emailengine.app/docker-compose.yml\ndocker compose up -d", "http": "curl \"https://emailengine.example.com/v1/account/user@example.com/messages?path=INBOX\u0026page=0\u0026pageSize=50\" \\\n -H \"Authorization: Bearer YOUR_ACCESS_TOKEN\"", "claudeCode": "claude mcp add --transport http emailengine https://emailengine.example.com/mcp \\\n --header \"Authorization: Bearer YOUR_ACCESS_TOKEN\"", "config": { "mcpServers": { "emailengine": { "headers": { "Authorization": "Bearer YOUR_ACCESS_TOKEN" }, "type": "http", "url": "https://emailengine.example.com/mcp" } } } }, "letme": { "capability": "https://letme.dev/mailbox.read", "tool": "https://letme.dev/emailengine" }, "area": "communication", "unitPrices": [ { "item": "EmailEngine subscription, $1,450 billed yearly", "unit": "month", "usd": 120.83, "note": "unlimited mailboxes, instances and API calls, VAT excluded, 14-day trial without a card" } ], "provenance": { "legalEntity": "Postal Systems OÜ, Narva mnt 5, 10117 Tallinn, Estonia, registry code 14971894", "domain": "emailengine.app", "domainRegistered": "2021-07-28", "endpointOnVendorDomain": null, "terms": "https://postalsys.com/tos", "privacy": "https://emailengine.app/privacy-policy", "statusPage": "", "changelog": "https://github.com/postalsys/emailengine/blob/master/CHANGELOG.md", "securityTxt": "valid", "checked": "2026-10-08", "notes": [ "The about page names Postal Systems OÜ at Narva mnt 5, 10117 Tallinn, with registry code 14971894 and VAT number EE102255902, and says the company is run by one person.", "RDAP for emailengine.app shows registration on 28 July 2021 through Namecheap.", "emailengine.app/.well-known/security.txt is PGP-signed, expires on 1 June 2027 and points to GitHub private advisories and SECURITY.md. postalsys.com has its own security.txt with no Expires field.", "The terms of service at postalsys.com/tos are dated 14 May 2020 and cover the subscription. The software licence is the EmailEngine licence agreement, version 2.1 of 17 October 2023, governed by Estonian law.", "The privacy policy at emailengine.app/privacy-policy has an effective date of 29 July 2026 and covers the website and the licence account, with Stripe named for payments.", "The API runs on the owner's instance, so there is no vendor endpoint and no status page." ], "score": 76 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/emailengine.json", "live": { "slug": "emailengine", "versions": [ { "registry": "github", "name": "postalsys/emailengine", "version": "v2.83.0", "released": "2026-10-08", "seenAt": "2026-10-08T16:10:38.546496352Z" }, { "registry": "npm", "name": "emailengine-app", "version": "2.83.0", "seenAt": "2026-10-08T16:10:36.788101811Z" } ], "githubStars": 2238, "npmWeekly": 388, "securityTxt": { "url": "https://emailengine.app/.well-known/security.txt", "state": "valid", "expires": "2027-06-01T00:00:00.000Z", "checkedAt": "2026-10-08T15:39:10.386155427Z" }, "pages": [ { "url": "https://raw.githubusercontent.com/postalsys/emailengine/master/CHANGELOG.md", "kind": "changelog", "status": 200, "checkedAt": "2026-10-08T18:24:39.774413238Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "92032edad8ba" }, { "url": "https://emailengine.app/privacy-policy", "kind": "privacy", "status": 200, "checkedAt": "2026-10-08T18:20:06.567354333Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "bf031c33ef50" }, { "url": "https://postalsys.com/tos", "kind": "terms", "status": 200, "checkedAt": "2026-10-08T18:23:11.919567662Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "cb7a76a9cb6a" } ], "updatedAt": "2026-10-08T18:24:39.774413238Z" } }, "answer": "EmailEngine scores 71.4 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories.", "b": { "slug": "unipile", "name": "Unipile", "vendor": "UNIPILE SAS", "vendorUrl": "https://www.unipile.com", "kind": "http-api", "category": "mailbox-access", "summary": "Unipile is a hosted API from Unipile SAS in France that connects to accounts people already have. It reads, searches, sends and files mail in Gmail, Outlook and IMAP mailboxes, and also covers calendars, LinkedIn, WhatsApp, Instagram and Telegram.", "url": "https://www.anchorterminal.com/tools/unipile", "markdownUrl": "https://www.anchorterminal.com/tools/unipile.md", "slimMarkdownUrl": "https://www.anchorterminal.com/tools/unipile.min.md", "jsonUrl": "https://www.anchorterminal.com/api/v1/tools/unipile.json", "repo": "https://github.com/unipile/unipile-node-sdk", "license": "Proprietary service under Unipile's terms of use. The v1 Node SDK repository and the unipile-mcp repository carry an MIT licence file", "transports": [ "http", "streamable-http" ], "remoteUrl": "https://developer.unipile.com/mcp?branch=v1.0", "packages": [ { "registry": "npm", "name": "unipile-node-sdk" } ], "auth": "api-key", "authNotes": "Self-serve. A person signs up at dashboard.unipile.com, copies the account's DSN (host and port) and generates an access token, which goes in the `X-API-KEY` header. A v1 token reaches every connected account and has no scopes. Mailboxes are connected by the end user through Google or Microsoft OAuth, using an OAuth app the customer registers and has verified, or with IMAP and SMTP credentials. The v2 beta adds keys limited to a Scope of accounts.", "pricing": "paid", "pricingNotes": "55 dollars (49 euros) a month covers up to 10 connected accounts, then 5.50 dollars an account a month, falling to 3.50 above 5,000. No charge per request or message. A 7-day trial needs no card, and there is no free tier after it. An SLA needs a custom plan (checked 2026-10-08).", "priceSummary": "$55 / mo", "where": "hosted", "x402": { "level": "no", "evidence": "No x402, MPP or L402 in the developer docs, the OpenAPI spec or the pricing page (checked 2026-10-08).", "endpoints": [] }, "toolCount": 5, "popularity": { "githubStars": 48, "npmWeekly": 82529, "pypiWeekly": null, "asOf": "2026-10-08" }, "docsUrl": "https://developer.unipile.com", "llmsTxt": "https://developer.unipile.com/llms.txt", "openapi": "https://api1.unipile.com/api-json?port=13111", "registryName": "com.unipile/unipile-mcp", "capabilities": [ "mailbox.read", "mailbox.search", "mailbox.send", "mailbox.drafts", "mailbox.sync", "calendar.read", "calendar.write", "calendar.webhooks", "messaging.whatsapp", "messaging.inbound" ], "tags": [ "hosted", "paid", "free-trial", "no-card", "api-key", "openapi", "llms-txt", "mcp", "webhooks", "gmail", "outlook", "imap", "calendar", "linkedin", "whatsapp", "typescript", "eu", "soc2", "status-page", "closed-source" ], "lastRelease": "2026-09-02", "graded": true, "anchor": { "graded": true, "score": 58.4, "grade": "C", "agentReady": false, "rank": 402, "ranked": true, "rankOf": 629, "categoryRank": 5, "methodology": "0.4", "run": "2026-10-01", "scores": { "ergonomics": 73, "maintenance": 59, "payments": 40, "reliability": 56, "schema": 77, "security": 37, "transparency": 71 }, "pending": [ "performance", "tasks" ], "assessment": { "confidence": "medium", "date": "2026-10-08" }, "negative": 0, "verdict": "One REST API covers Gmail, Outlook and IMAP with search, drafts, send with an idempotency key and new-mail webhooks, and the OpenAPI spec is public. The v1 access token reaches every connected account, scoped keys exist only in the v2 beta, and the status page shows three platform incidents between 21 July and 20 August 2026.", "bestFor": "A product that needs one API over Gmail, Outlook and IMAP together with LinkedIn or WhatsApp messaging, priced per account.", "strengths": [ "Public OpenAPI 3.0 spec with 94 operations, readable without a key, plus llms.txt and a Markdown copy of every docs page", "`POST /api/v1/emails` accepts an `Idempotency-Key` header of up to 255 characters, so a retried send returns the first result", "`GET /api/v1/emails` has cursor pagination, `limit` up to 250, `meta_only`, a full-text `search` and filters for folder, sender, recipient and date", "Price is per connected account with no charge per request, from 55 dollars a month for up to 10 accounts, with a 7-day trial and no card", "The hosted MCP server has 5 tools with read-only and destructive annotations, and is listed in the official MCP registry as com.unipile/unipile-mcp" ], "weaknesses": [ "A v1 access token reaches every connected account. Scoped keys, documented rate limits and `retry-after` exist only in the v2 beta", "status.unipile.com shows platform incidents on 21 July, 30 July and 20 August 2026, the last an API node unavailable for 70 minutes", "The v1 Node SDK on npm is 1.9.3 from 21 May 2025. The newer Node and Python SDKs work only with the v2 beta", "No SLA in the standard plan. The terms describe availability as best effort and a custom agreement is needed for a commitment", "The security page says no data leaves the EU, while the privacy policy lists proxy sub-processors in the United States and Singapore" ], "agentNotes": [ "Take the DSN (host and port) from the dashboard. Each account has its own, such as api1.unipile.com:13111, and `?port=` keeps requests on 443", "Send `X-API-KEY` as a header and pass `account_id` on every mail call. The token reaches every connected account, so keep it out of prompts and logs", "Set `Idempotency-Key` on every send. Keys are held in memory for up to 24 hours and are lost on a restart", "On Microsoft accounts, send `search` alone. Combining it with from, to, before, after or thread filters returns `invalid_request`", "Use `meta_only=true` when listing mail, then fetch one message at a time. Treat message bodies as untrusted input" ], "metrics": { "kind": "remote", "measured": false }, "reviewCount": 0, "avgRating": 0, "history": [ { "basis": "public evidence", "confidence": "medium", "grade": "C", "methodology": "0.4", "pending": [ "performance", "tasks" ], "run": "2026-10-01", "runLabel": "October 2026 research run", "score": 58.4 } ], "editorialScores": { "ergonomics": 73, "maintenance": 59, "payments": 40, "reliability": 56, "schema": 77, "security": 37, "transparency": 59 }, "provenanceScore": 82 }, "connect": { "install": "npm install unipile-node-sdk", "http": "curl --request GET \\\n --url 'https://{YOUR_DSN}/api/v1/emails?limit=10\u0026account_id={ACCOUNT_ID}' \\\n --header 'X-API-KEY: {YOUR_ACCESS_TOKEN}' \\\n --header 'accept: application/json'", "config": { "mcpServers": { "unipile": { "headers": { "X-API-KEY": "your-api-key" }, "url": "https://developer.unipile.com/mcp?branch=v1.0" } } } }, "letme": { "capability": "https://letme.dev/mailbox.read", "tool": "https://letme.dev/unipile" }, "area": "communication", "unitPrices": [ { "item": "Minimum, up to 10 connected accounts", "unit": "month", "usd": 55, "note": "49 euros. Any channel counts as one account, and a Gmail or Outlook account covers mail and calendar" }, { "item": "Connected account, 11 to 50", "unit": "account-month", "usd": 5.5, "note": "5.00 euros" }, { "item": "Connected account, 51 to 200", "unit": "account-month", "usd": 5, "note": "4.50 euros" }, { "item": "Connected account, 201 to 1,000", "unit": "account-month", "usd": 4.5, "note": "4.00 euros" }, { "item": "Connected account, 1,001 to 5,000", "unit": "account-month", "usd": 4, "note": "3.50 euros" }, { "item": "Connected account, 5,001 and above", "unit": "account-month", "usd": 3.5, "note": "3.00 euros" } ], "provenance": { "legalEntity": "UNIPILE SAS", "domain": "unipile.com", "domainRegistered": "2020-11-17", "endpointOnVendorDomain": true, "terms": "https://www.unipile.com/terms-of-use/", "privacy": "https://www.unipile.com/privacy-policy/", "statusPage": "https://status.unipile.com", "changelog": "https://developer.unipile.com/changelog", "securityTxt": "none", "checked": "2026-10-08", "notes": [ "The legal notice names UNIPILE SAS, registered with the RCS of Roanne under number 885265595, head office 168 rue de la Rotonde, 42153 Riorges, France.", "The API answers on a per-account host and port under unipile.com, such as api1.unipile.com:13111. The MCP server is at developer.unipile.com/mcp, a ReadMe-hosted docs site on the vendor's domain.", "www.unipile.com/.well-known/security.txt returns 404. No vulnerability disclosure policy or bug bounty was found on the security page.", "The terms are governed by French law, with the Commercial Court of Roanne as the court. They say changes take effect on publication.", "RDAP for unipile.com gives a registration date of 2020-11-17." ], "score": 82 }, "pageJsonUrl": "https://www.anchorterminal.com/tools/unipile.json", "live": { "slug": "unipile", "probe": { "target": "https://developer.unipile.com/mcp?branch=v1.0", "method": "get", "lastAt": "2026-10-08T19:09:01.147207455Z", "lastOk": true, "lastStatus": 200, "lastMs": 37, "authRequired": false, "uptime24h": 100, "uptime30d": 100, "p50ms24h": 55, "p95ms24h": 115, "samples24h": 42, "samples30d": 42, "days": [ { "date": "2026-10-08", "probes": 42, "ok": 42 } ] }, "vendorStatus": { "page": "https://status.unipile.com", "indicator": "unknown", "summary": "no machine-readable status found", "checkedAt": "2026-10-08T17:51:16.923603697Z" }, "versions": [ { "registry": "github", "name": "unipile/unipile-node-sdk", "version": "v1.9.3", "released": "2025-05-21", "seenAt": "2026-10-08T16:33:19.750124079Z" }, { "registry": "npm", "name": "unipile-node-sdk", "version": "1.9.3", "seenAt": "2026-10-08T16:33:18.965183575Z" } ], "githubStars": 48, "npmWeekly": 82529, "securityTxt": { "url": "https://unipile.com/.well-known/security.txt", "state": "none", "checkedAt": "2026-10-08T15:38:37.558927605Z" }, "pages": [ { "url": "https://developer.unipile.com/changelog", "kind": "changelog", "status": 200, "checkedAt": "2026-10-08T18:17:20.678778332Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "14178c9246c1" }, { "url": "https://www.unipile.com/privacy-policy/", "kind": "privacy", "status": 200, "checkedAt": "2026-10-08T18:31:12.004667145Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "cbc48f825ecc" }, { "url": "https://www.unipile.com/terms-of-use/", "kind": "terms", "status": 200, "checkedAt": "2026-10-08T18:31:14.04469123Z", "changedAt": "0001-01-01T00:00:00Z", "fingerprint": "3d0b4ec6b8b4" } ], "updatedAt": "2026-10-08T19:09:01.147207455Z" } }, "facts": [ { "a": "HTTP API", "b": "HTTP API", "name": "Kind" }, { "a": "Postal Systems OÜ", "b": "UNIPILE SAS", "name": "Vendor" }, { "a": "no (local only)", "b": "https://developer.unipile.com/mcp?branch=v1.0", "name": "Hosted endpoint" }, { "a": "HTTP", "b": "HTTP, Streamable HTTP", "name": "Transports" }, { "a": "API key", "b": "API key", "name": "Auth" }, { "a": "Paid", "b": "Paid", "name": "Pricing" }, { "a": "no", "b": "no", "name": "x402" }, { "a": "Source available under the EmailEngine licence agreement, version 2.1 of 17 October 2023. Not open source. The PHP SDK is MIT", "b": "Proprietary service under Unipile's terms of use. The v1 Node SDK repository and the unipile-mcp repository carry an MIT licence file", "name": "Licence" }, { "a": "none", "b": "5", "name": "Tools exposed" }, { "a": "no", "b": "yes", "name": "Read-only variant documented" }, { "a": "yes", "b": "yes", "name": "llms.txt" }, { "a": "not listed", "b": "com.unipile/unipile-mcp", "name": "MCP registry" }, { "a": "2026-10-05", "b": "2026-09-02", "name": "Last release" }, { "a": "no date given", "b": "no date given", "name": "Terms last updated" }, { "a": "no date given", "b": "2026-09-28", "name": "Privacy policy last updated" }, { "a": "not found in the text", "b": "not found in the text", "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": "yes", "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": "2.2k stars, 388 npm/wk", "b": "48 stars, 83k npm/wk", "name": "Popularity" } ], "faq": [ { "answer": "EmailEngine scores 71.4 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories.", "question": "Which is better for AI agents, EmailEngine or Unipile?" }, { "answer": "Both need an API key.", "question": "Do EmailEngine and Unipile need an API key?" }, { "answer": "No hosted endpoint is listed for EmailEngine. Unipile has a hosted endpoint at https://developer.unipile.com/mcp?branch=v1.0.", "question": "Can an agent call EmailEngine and Unipile without installing anything?" } ], "goodFor": [ { "aheadOn": [ "Reliability, 79 against 56", "Schema \u0026 documentation, 91 against 77", "Agent ergonomics, 80 against 73", "Security \u0026 auth, 71 against 37", "Maintenance \u0026 community, 81 against 59" ], "also": [ "Agent-ready, a grade of BB or better" ], "goodFor": "A team that must keep mailbox access on its own infrastructure, has many mailboxes across Gmail, Microsoft 365 and IMAP, and can run a server and Redis.", "slug": "emailengine", "watchFor": "Not open source. Running it beyond the 14-day trial needs a subscription at $1,450 or EUR 1,200 a year" }, { "aheadOn": null, "also": [ "A hosted endpoint, with nothing to install", "Free to start without a card", "No incidents deducted, where EmailEngine loses 3 points for them" ], "goodFor": "A product that needs one API over Gmail, Outlook and IMAP together with LinkedIn or WhatsApp messaging, priced per account.", "slug": "unipile", "watchFor": "A v1 access token reaches every connected account. Scoped keys, documented rate limits and `retry-after` exist only in the v2 beta" } ], "job": { "capability": "mailbox.read", "name": "Mailbox read" }, "others": [ { "json": "https://www.anchorterminal.com/compare/emailengine-vs-gmail-api.json", "title": "EmailEngine vs Gmail API", "url": "https://www.anchorterminal.com/compare/emailengine-vs-gmail-api" }, { "json": "https://www.anchorterminal.com/compare/emailengine-vs-nylas-email.json", "title": "EmailEngine vs Nylas Email API", "url": "https://www.anchorterminal.com/compare/emailengine-vs-nylas-email" }, { "json": "https://www.anchorterminal.com/compare/emailengine-vs-outlook-mail-graph.json", "title": "EmailEngine vs Outlook Mail (Microsoft Graph)", "url": "https://www.anchorterminal.com/compare/emailengine-vs-outlook-mail-graph" }, { "json": "https://www.anchorterminal.com/compare/gmail-api-vs-unipile.json", "title": "Gmail API vs Unipile", "url": "https://www.anchorterminal.com/compare/gmail-api-vs-unipile" }, { "json": "https://www.anchorterminal.com/compare/nylas-email-vs-unipile.json", "title": "Nylas Email API vs Unipile", "url": "https://www.anchorterminal.com/compare/nylas-email-vs-unipile" }, { "json": "https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.json", "title": "Outlook Mail (Microsoft Graph) vs Unipile", "url": "https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile" } ], "scores": [ { "by": 23, "edge": "emailengine", "emailengine": 79, "key": "reliability", "name": "Reliability", "unipile": 56, "weight": 16 }, { "key": "performance", "name": "Performance", "pending": true, "weight": 10 }, { "by": 14, "edge": "emailengine", "emailengine": 91, "key": "schema", "name": "Schema \u0026 documentation", "unipile": 77, "weight": 13 }, { "by": 7, "edge": "emailengine", "emailengine": 80, "key": "ergonomics", "name": "Agent ergonomics", "unipile": 73, "weight": 13 }, { "by": 34, "edge": "emailengine", "emailengine": 71, "key": "security", "name": "Security \u0026 auth", "unipile": 37, "weight": 14 }, { "by": 0, "edge": "", "emailengine": 40, "key": "payments", "name": "Payments \u0026 pricing", "unipile": 40, "weight": 10 }, { "key": "tasks", "name": "Task success", "pending": true, "weight": 10 }, { "by": 22, "edge": "emailengine", "emailengine": 81, "key": "maintenance", "name": "Maintenance \u0026 community", "unipile": 59, "weight": 7 }, { "by": 1, "edge": "emailengine", "emailengine": 72, "key": "transparency", "name": "Transparency \u0026 trust", "unipile": 71, "weight": 7 } ], "summary": "EmailEngine scores 71.4 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Both do mailbox read.", "verdicts": { "emailengine": "A self-hosted REST API over Gmail, Microsoft 365 and IMAP, with a public OpenAPI 3.0 spec and tokens that can be bound to one account, limited by action and group, and rate limited. It needs a server, Redis and a $1,450 yearly licence after a 14-day trial, and the MCP endpoint is a beta, off by default.", "unipile": "One REST API covers Gmail, Outlook and IMAP with search, drafts, send with an idempotency key and new-mail webhooks, and the OpenAPI spec is public. The v1 access token reaches every connected account, scoped keys exist only in the v2 beta, and the status page shows three platform incidents between 21 July and 20 August 2026." } }, "kind": "anchor.page", "links": { "api": "https://www.anchorterminal.com/api/v1/index.json", "html": "https://www.anchorterminal.com/compare/emailengine-vs-unipile", "json": "https://www.anchorterminal.com/compare/emailengine-vs-unipile.json", "llms": "https://www.anchorterminal.com/llms.txt", "markdown": "https://www.anchorterminal.com/compare/emailengine-vs-unipile.md", "slim": "https://www.anchorterminal.com/compare/emailengine-vs-unipile.min.md" }, "markdown": "EmailEngine scores 71.4 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Both do mailbox read.\n\n- EmailEngine: grade BB, 71.4/100, rank #106 of 629. Markdown https://www.anchorterminal.com/tools/emailengine.md · JSON https://www.anchorterminal.com/api/v1/tools/emailengine.json\n- Unipile: grade C, 58.4/100, rank #402 of 629. Markdown https://www.anchorterminal.com/tools/unipile.md · JSON https://www.anchorterminal.com/api/v1/tools/unipile.json\n\n## Which one, for what\n\n### EmailEngine (BB)\n\nGood for: A team that must keep mailbox access on its own infrastructure, has many mailboxes across Gmail, Microsoft 365 and IMAP, and can run a server and Redis.\n\nAhead on:\n- Reliability, 79 against 56\n- Schema \u0026 documentation, 91 against 77\n- Agent ergonomics, 80 against 73\n- Security \u0026 auth, 71 against 37\n- Maintenance \u0026 community, 81 against 59\n\nAlso in its favour:\n- Agent-ready, a grade of BB or better\n\nWatch for: Not open source. Running it beyond the 14-day trial needs a subscription at $1,450 or EUR 1,200 a year\n\n### Unipile (C)\n\nGood for: A product that needs one API over Gmail, Outlook and IMAP together with LinkedIn or WhatsApp messaging, priced per account.\n\nAlso in its favour:\n- A hosted endpoint, with nothing to install\n- Free to start without a card\n- No incidents deducted, where EmailEngine loses 3 points for them\n\nWatch for: A v1 access token reaches every connected account. Scoped keys, documented rate limits and `retry-after` exist only in the v2 beta\n\n\n## Score by category\n\n| Category | Weight | EmailEngine | Unipile | Edge |\n| --- | --- | --- | --- | --- |\n| Reliability | 16% (20 this run) | 79 | 56 | EmailEngine +23 |\n| Performance | 10%, pending | pending | pending | not scored in this run |\n| Schema \u0026 documentation | 13% (16.2 this run) | 91 | 77 | EmailEngine +14 |\n| Agent ergonomics | 13% (16.2 this run) | 80 | 73 | EmailEngine +7 |\n| Security \u0026 auth | 14% (17.5 this run) | 71 | 37 | EmailEngine +34 |\n| Payments \u0026 pricing | 10% (12.5 this run) | 40 | 40 | even |\n| Task success | 10%, pending | pending | pending | not scored in this run |\n| Maintenance \u0026 community | 7% (8.8 this run) | 81 | 59 | EmailEngine +22 |\n| Transparency \u0026 trust | 7% (8.8 this run) | 72 | 71 | EmailEngine +1 |\n| Negative events | ≤15 | -3 | 0 | |\n| **Total** | | **71.4 · BB** | **58.4 · C** | |\n\n## Facts side by side\n\n| Fact | EmailEngine | Unipile |\n| --- | --- | --- |\n| Kind | HTTP API | HTTP API |\n| Vendor | Postal Systems OÜ | UNIPILE SAS |\n| Hosted endpoint | no (local only) | `https://developer.unipile.com/mcp?branch=v1.0` |\n| Transports | HTTP | HTTP, Streamable HTTP |\n| Auth | API key | API key |\n| Pricing | Paid | Paid |\n| x402 | no | no |\n| Licence | Source available under the EmailEngine licence agreement, version 2.1 of 17 October 2023. Not open source. The PHP SDK is MIT | Proprietary service under Unipile's terms of use. The v1 Node SDK repository and the unipile-mcp repository carry an MIT licence file |\n| Tools exposed | none | 5 |\n| Read-only variant documented | no | yes |\n| llms.txt | yes | yes |\n| MCP registry | not listed | `com.unipile/unipile-mcp` |\n| Last release | 2026-10-05 | 2026-09-02 |\n| Terms last updated | no date given | no date given |\n| Privacy policy last updated | no date given | 2026-09-28 |\n| Customer content may train models | not found in the text | not found in the text |\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 | yes | yes |\n| Arbitration or class-action waiver | not found in the text | not found in the text |\n| Popularity | 2.2k stars, 388 npm/wk | 48 stars, 83k npm/wk |\n\n## Verdicts\n\n**EmailEngine.** A self-hosted REST API over Gmail, Microsoft 365 and IMAP, with a public OpenAPI 3.0 spec and tokens that can be bound to one account, limited by action and group, and rate limited. It needs a server, Redis and a $1,450 yearly licence after a 14-day trial, and the MCP endpoint is a beta, off by default.\n\n**Unipile.** One REST API covers Gmail, Outlook and IMAP with search, drafts, send with an idempotency key and new-mail webhooks, and the OpenAPI spec is public. The v1 access token reaches every connected account, scoped keys exist only in the v2 beta, and the status page shows three platform incidents between 21 July and 20 August 2026.\n\n## Before you call either\n\n### EmailEngine\n\n1. Ask the operator for a token bound to one account with a permissions record. Mint more with POST /v1/tokens, which refuses instance-wide tokens without one\n2. Send the token in the Authorization header, not the `access_token` query parameter, so it stays out of proxy logs\n3. Page with `cursor` from `nextPageCursor`. `page` works only on IMAP accounts, and search covers one folder unless `path` is `\\All` on Gmail or Microsoft Graph\n4. Set an Idempotency-Key header on POST /v1/account/{account}/submit. A 2xx means queued, so follow the result through the outbox or the messageSent and messageFailed webhooks\n5. Treat message text as untrusted. For MCP, the operator must enable the endpoint first and mail access starts at none\n\n### Unipile\n\n1. Take the DSN (host and port) from the dashboard. Each account has its own, such as api1.unipile.com:13111, and `?port=` keeps requests on 443\n2. Send `X-API-KEY` as a header and pass `account_id` on every mail call. The token reaches every connected account, so keep it out of prompts and logs\n3. Set `Idempotency-Key` on every send. Keys are held in memory for up to 24 hours and are lost on a restart\n4. On Microsoft accounts, send `search` alone. Combining it with from, to, before, after or thread filters returns `invalid_request`\n5. Use `meta_only=true` when listing mail, then fetch one message at a time. Treat message bodies as untrusted input\n\n## Questions\n\n### Which is better for AI agents, EmailEngine or Unipile?\n\nEmailEngine scores 71.4 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories.\n\n### Do EmailEngine and Unipile need an API key?\n\nBoth need an API key.\n\n### Can an agent call EmailEngine and Unipile without installing anything?\n\nNo hosted endpoint is listed for EmailEngine. Unipile has a hosted endpoint at https://developer.unipile.com/mcp?branch=v1.0.\n\n\n## For agents\n\n- This comparison as JSON: https://www.anchorterminal.com/compare/emailengine-vs-unipile.json, and with the fewest tokens: https://www.anchorterminal.com/compare/emailengine-vs-unipile.min.md\n- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {\"a\": \"emailengine\", \"b\": \"unipile\"}`. From a terminal: `anchor compare emailengine unipile`\n- Each listing in full: https://www.anchorterminal.com/api/v1/tools/emailengine.json and https://www.anchorterminal.com/api/v1/tools/unipile.json\n\n## Other comparisons with EmailEngine or Unipile\n\n- [EmailEngine vs Gmail API](https://www.anchorterminal.com/compare/emailengine-vs-gmail-api.md)\n- [EmailEngine vs Nylas Email API](https://www.anchorterminal.com/compare/emailengine-vs-nylas-email.md)\n- [EmailEngine vs Outlook Mail (Microsoft Graph)](https://www.anchorterminal.com/compare/emailengine-vs-outlook-mail-graph.md)\n- [Gmail API vs Unipile](https://www.anchorterminal.com/compare/gmail-api-vs-unipile.md)\n- [Nylas Email API vs Unipile](https://www.anchorterminal.com/compare/nylas-email-vs-unipile.md)\n- [Outlook Mail (Microsoft Graph) vs Unipile](https://www.anchorterminal.com/compare/outlook-mail-graph-vs-unipile.md)\n", "meta": { "attribution": "Anchor Terminal (https://www.anchorterminal.com)", "docs": "https://www.anchorterminal.com/docs/", "generatedAt": "2026-10-08", "license": "CC-BY-4.0", "method": "https://www.anchorterminal.com/benchmark/", "methodology": "0.4", "openapi": "https://www.anchorterminal.com/openapi.json", "preview": false, "run": "2026-10-01", "runLabel": "October 2026 research run" }, "page": { "breadcrumbs": [ { "name": "Home", "url": "https://www.anchorterminal.com/" }, { "name": "Compare", "url": "https://www.anchorterminal.com/compare/" }, { "name": "EmailEngine vs Unipile", "url": "" } ], "description": "EmailEngine scores 71.4 (BB) on agent readiness against Unipile's 58.4 (C), and leads in 6 of 7 scored categories. Both do mailbox read. Category scores, facts, verdicts and agent notes side by side.", "facts": [ "EmailEngine BB 71.4", "Unipile C 58.4", "scores" ], "h1": "EmailEngine vs Unipile", "image": "https://www.anchorterminal.com/assets/og/compare-emailengine-vs-unipile.png", "path": "/compare/emailengine-vs-unipile", "published": "2026-10-01", "section": "tools", "title": "EmailEngine vs Unipile for AI agents, BB 71.4 vs C 58.4", "toc": null, "updated": "2026-10-08", "url": "https://www.anchorterminal.com/compare/emailengine-vs-unipile" }, "tokens": { "markdown": 2050, "slim": 680 }, "version": 1 }