Send an email now
Sends an email immediately from one of the workspace mailboxes. The only irreversible action of the API: it reaches a third party.
To reply in a thread: send from the mailboxId of the original, set inReplyTo to its messageId, references to its references followed by its messageId, and prefix the subject with Re: .
Signatures: inserted by default, exactly as for POST /drafts ("default", "none" or a signature id), resolved on the from alias when given, otherwise on the mailbox address. Your HTML is sent as is.
Always send an Idempotency-Key. Known issue: if the message left but a later step failed (copy to the Sent folder, disconnection), the API answers 500 INTERNAL_ERROR and releases the idempotency key, so a retry sends the message a second time. After a 500, check the SENT folder before retrying.
Fires a draft.sent webhook. Attachments cannot be sent through the API.
Authorization
apiKey Your 48 character Emelia API key, the same as for the Emelia API, sent as is (a Bearer prefix is tolerated). Create it at https://v3.emelia.io/settings/api. Disabling a key can take up to 5 minutes to apply to the Inbox API.
In: header
Header Parameters
Any unique string (a UUID). The first successful response is stored 24 hours and replayed with Idempotent-Replay: true for the same key, method, URL and body. Same key with another body: 409 CONFLICT. Original call still running: 409 CONFLICT. Failed calls (status 400 and above) release the key. Keys are scoped to the workspace, not to the API key: two integrations of the same workspace must not reuse values. Replays count in the quotas.
length <= 255Request Body
application/json
TypeScript Definitions
Use the request body type in TypeScript.
Response Body
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
application/json
curl -X POST "https://example.com/drafts/send" \ -H "Authorization: YOUR_API_KEY" \ -H "Idempotency-Key: 3f6c1b2e-7d4a-4f0e-9a51-acme00000001" \ -H "Content-Type: application/json" \ -d '{ "mailboxId": "cmbxacme0000000000000001", "to": [ { "email": "jane.roe@example.com", "name": "Jane Roe" } ], "subject": "Re: Partnership with Acme", "inReplyTo": "<CAJacme.0001@mail.example.com>", "references": [ "<20261008091500.acme01@acme.com>", "<CAJacme.0001@mail.example.com>" ], "body": { "text": "Hello Jane,\\n\\nTuesday 10am works for me.", "html": "<p>Hello Jane,</p><p>Tuesday 10am works for me.</p>" }, "signature": "default" }'{ "messageId": "<20261008100233.acme02@acme.com>", "threadId": "18c2acme0001"}