Send email

Send an email from an inbox. Requires Idempotency-Key header. Use threadId to reply to an existing thread. When replying on a thread where your inbox was CC’d (deliveryRole cc), the original sender is automatically CC’d.

POST /v1/inboxes/{id}/send

Send email

cURL

curl --request POST \
  --url https://api.openmail.sh/v1/inboxes/{id}/send \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'Idempotency-Key: <idempotency-key>' \
  --data '
{
  "to": "[e-mail]",
  "body": "<string>",
  "subject": "<string>",
  "bodyHtml": "<string>",
  "threadId": "<string>",
  "includeQuote": true,
  "replyTo": "[e-mail]",
  "cc": [
    "[e-mail]"
  ]
}
'

200

{
  "messageId": "<string>",
  "threadId": "<string>",
  "providerMessageId": "<string>"
}

Authorizations

Authorization · string · header · required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Headers

Idempotency-Key · string · required

Unique key for idempotent sends (e.g. UUID)

Path Parameters

id · string · required

Body

application/jsonmultipart/form-data

to · string<email> · required

body · string · required

Email body. Plain text or HTML — HTML is auto-detected and rendered, with a plain-text fallback generated automatically.

Required string length: 1 - 100000

subject · string

Required for new threads. Optional when threadId is set — the thread subject is used automatically (with Re: prefix).

Required string length: 1 - 998

bodyHtml · string

Provide only when the plain-text and HTML versions must differ. Omit for normal sends — put HTML in body instead.

Maximum string length: 500000

threadId · string

Thread ID for replies

includeQuote · boolean

When replying with threadId, append a quoted copy of the previous message to the body. Defaults to true. Set false to send only your reply text.

replyTo · string<email>

Optional. Address that replies should be routed to (set as the Reply-To MIME header). Free plan: must be the address of an inbox you own in OpenMail. Developer plan or higher: any valid email address.

cc · string<email>[]

Optional CC recipients.

Response

200

application/json

Email sent (or idempotent replay)

messageId · string

threadId · string

providerMessageId · string

status · enum<string>

Available options: pending, sent, failed