Aurinko Email API vs Unipile

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.

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.

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

Unipile

1. 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
2. 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
3. Set Idempotency-Key on every send. Keys are held in memory for up to 24 hours and are lost on a restart
4. On Microsoft accounts, send search alone. Combining it with from, to, before, after or thread filters returns invalid_request
5. Use meta_only=true when listing mail, then fetch one message at a time. Treat message bodies as untrusted input