Aurinko Email API vs Outlook Mail (Microsoft Graph)

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.

Outlook Mail (Microsoft Graph)

Delegated permissions split reading without bodies (Mail.ReadBasic), full reading, writing and sending, and delta queries and change notifications keep a local copy in step. sendMail takes no idempotency key and returns 202 before delivery, and each app is held to four concurrent requests per mailbox.

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

Outlook Mail (Microsoft Graph)

1. Create a draft with POST /me/messages, then send it with /send. A retried sendMail can send the message twice
2. Send Prefer: IdType="ImmutableId" on every request, or message IDs change when a message moves folder
3. Use $select and Prefer: outlook.body-content-type="text". List messages returns HTML bodies and 10 messages a page by default
4. Honour Retry-After on 429 and keep to four parallel calls per mailbox. Batches of up to 20 requests are throttled per request
5. Treat message bodies as untrusted input, and ask for Mail.ReadBasic when the task doesn't need bodies