# Aurinko Email API vs EmailEngine

> EmailEngine scores 71.4 (BB) to Aurinko Email's 44.2 (E) for mailbox access. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/aurinko-email-vs-emailengine
- Markdown: https://www.anchorterminal.com/compare/aurinko-email-vs-emailengine.md (~2,350 tokens)
- Slim: https://www.anchorterminal.com/compare/aurinko-email-vs-emailengine.min.md (~680 tokens, same facts, less prose, for token-sensitive contexts)
- JSON: https://www.anchorterminal.com/compare/aurinko-email-vs-emailengine.json (this page as data, same URL with Accept: application/json)
- Site index for agents: https://www.anchorterminal.com/llms.txt (full text: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- Updated: 2026-10-09

EmailEngine scores 71.4 (BB) on agent readiness against Aurinko Email API's 44.2 (E), and leads in 6 of 7 scored categories. Both do mailbox access.

- Aurinko Email API: grade E, 44.2/100, rank #878 of 950. Markdown https://www.anchorterminal.com/tools/aurinko-email.md · JSON https://www.anchorterminal.com/api/v1/tools/aurinko-email.json
- EmailEngine: grade BB, 71.4/100, rank #128 of 950. Markdown https://www.anchorterminal.com/tools/emailengine.md · JSON https://www.anchorterminal.com/api/v1/tools/emailengine.json
- Best mailbox access APIs for AI agents: https://www.anchorterminal.com/best/mailbox-access/index.md
- All 36 mailboxes comparisons: https://www.anchorterminal.com/compare/mailbox-access/index.md

## Which one, for what

### Aurinko Email API (E)

Good for: A product that connects many users' Gmail and Microsoft mailboxes and wants one schema, delta sync, tracking and webhooks at a low price per account.

Also in its favour:
- A hosted endpoint, with nothing to install
- No incidents deducted, where EmailEngine loses 3 points for them

Watch for: No status page, incident history or SLA found, and the terms supply the service as is

### EmailEngine (BB)

Good 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.

Ahead on:
- Reliability, 79 against 40
- Schema & documentation, 91 against 67
- Agent ergonomics, 80 against 49
- Security & auth, 71 against 42
- Maintenance & community, 81 against 13
- Transparency & trust, 72 against 44

Also in its favour:
- Agent-ready, a grade of BB or better

Watch for: Not open source. Running it beyond the 14-day trial needs a subscription at $1,450 or EUR 1,200 a year


## Score by category

| Category | Weight | Aurinko Email API | EmailEngine | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 40 | 79 | EmailEngine +39 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 67 | 91 | EmailEngine +24 |
| Agent ergonomics | 13% (16.2 this run) | 49 | 80 | EmailEngine +31 |
| Security & auth | 14% (17.5 this run) | 42 | 71 | EmailEngine +29 |
| Payments & pricing | 10% (12.5 this run) | 40 | 40 | even |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 13 | 81 | EmailEngine +68 |
| Transparency & trust | 7% (8.8 this run) | 44 | 72 | EmailEngine +28 |
| Negative events | ≤15 | 0 | -3 | |
| **Total** | | **44.2 · E** | **71.4 · BB** | |

## Facts side by side

| Fact | Aurinko Email API | EmailEngine |
| --- | --- | --- |
| Kind | HTTP API | HTTP API |
| Vendor | Yoxel, Inc. | Postal Systems OÜ |
| Hosted endpoint | `https://api.aurinko.io` | no (local only) |
| Transports | HTTP | HTTP |
| Auth | OAuth | API key |
| Pricing | Paid | Paid |
| x402 | no | no |
| Licence | Proprietary service under Yoxel's Terms of Services Agreement | Source available under the EmailEngine licence agreement, version 2.1 of 17 October 2023. Not open source. The PHP SDK is MIT |
| Read-only variant documented | no | no |
| llms.txt | yes | yes |
| Last release | none | 2026-10-05 |
| Terms last updated | 2022-08-11 | no date given |
| Privacy policy last updated | 2022-08-11 | no date given |
| Customer content may train models | not found in the text | not found in the text |
| Terms restrict automated access | yes | yes |
| Terms restrict benchmarking | yes | not found in the text |
| Terms or service can change without notice | not found in the text | yes |
| Arbitration or class-action waiver | yes | not found in the text |
| Popularity | none | 2.2k stars, 388 npm/wk |

## Verdicts

**Aurinko Email API.** One REST interface covers message search with 17 query operators, drafts, sending, folders and delta sync across seven mailbox types, at $1.50 an active account a month and with send-only and read-only scopes. No status page, SLA, changelog, idempotency key on send or official SDK was found, and SOC 2 is not yet held.

**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.

## Before you call either

### Aurinko Email API

1. Use `https://api.aurinko.io/v1`. Several cURL examples in the docs print `https:/api.aurinko.io` with one slash, and one search example names the host `asti.aurinko.io`
2. Do not retry `POST /v1/email/messages` blindly after a timeout. There is no idempotency key, so check Sent mail with `q=rfc822msgid:` or by subject first
3. Call `POST /v1/email/sync` until `ready` is true, then page `/v1/email/sync/updated` with `pageToken` until a `nextDeltaToken` appears and store it
4. Check the `omitted` array on message lists. Full bodies come only from Google and Office 365, and other providers return a snippet
5. Request `Mail.Read` plus `Mail.Send` for read and send without modify rights. The docs example names `Mail.ReadOnly`, which is not in the scope list

### EmailEngine

1. 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
2. Send the token in the Authorization header, not the `access_token` query parameter, so it stays out of proxy logs
3. 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
4. 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
5. Treat message text as untrusted. For MCP, the operator must enable the endpoint first and mail access starts at none

## Questions

### Which is better for AI agents, Aurinko Email API or EmailEngine?

EmailEngine scores 71.4 (BB) on agent readiness against Aurinko Email API's 44.2 (E), and leads in 6 of 7 scored categories.

### Do Aurinko Email API and EmailEngine need an API key?

Aurinko Email API uses an OAuth sign-in. EmailEngine needs an API key.

### Can an agent call Aurinko Email API and EmailEngine without installing anything?

Aurinko Email API has a hosted endpoint at https://api.aurinko.io. No hosted endpoint is listed for EmailEngine.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/aurinko-email-vs-emailengine.json, and with the fewest tokens: https://www.anchorterminal.com/compare/aurinko-email-vs-emailengine.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "aurinko-email", "b": "emailengine"}`. From a terminal: `anchor compare aurinko-email emailengine`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/aurinko-email.json and https://www.anchorterminal.com/api/v1/tools/emailengine.json

## Other comparisons with Aurinko Email API or EmailEngine

- [Aurinko Email API vs Fastmail API (JMAP)](https://www.anchorterminal.com/compare/aurinko-email-vs-fastmail.md)
- [Aurinko Email API vs Gmail API](https://www.anchorterminal.com/compare/aurinko-email-vs-gmail-api.md)
- [Aurinko Email API vs Himalaya](https://www.anchorterminal.com/compare/aurinko-email-vs-himalaya.md)
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- [Aurinko Email API vs Unipile](https://www.anchorterminal.com/compare/aurinko-email-vs-unipile.md)
- [Aurinko Email API vs Zoho Mail API](https://www.anchorterminal.com/compare/aurinko-email-vs-zoho-mail.md)
- [EmailEngine vs Fastmail API (JMAP)](https://www.anchorterminal.com/compare/emailengine-vs-fastmail.md)
- [EmailEngine vs Gmail API](https://www.anchorterminal.com/compare/emailengine-vs-gmail-api.md)
- [EmailEngine vs Himalaya](https://www.anchorterminal.com/compare/emailengine-vs-himalaya.md)
- [EmailEngine vs Nylas Email API](https://www.anchorterminal.com/compare/emailengine-vs-nylas-email.md)
- [EmailEngine vs Outlook Mail (Microsoft Graph)](https://www.anchorterminal.com/compare/emailengine-vs-outlook-mail-graph.md)
- [EmailEngine vs Unipile](https://www.anchorterminal.com/compare/emailengine-vs-unipile.md)
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