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POST
Send email

Authorizations

Authorization
string
header
required

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

Headers

idempotency-key
string

Optional. Unique key (e.g. UUID) that makes retries safe: a repeat with the same key within 24 hours returns the original message instead of sending again. Generated server-side when omitted.

Path Parameters

id
string
required

Body

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. Pro plan or higher: any valid email address.

cc
string<email>[]

Optional CC recipients. Visible to every recipient.

bcc
string<email>[]

Optional BCC recipients. Delivered, but omitted from the message To and Cc recipients can read. Use this for CRM logging addresses (for example HubSpot or Salesforce) that only record the email when they are in BCC. Checked against the inbox's outbound recipient policy, same as to and cc.

Response

Email sent (or idempotent replay)

Email sent (or idempotent replay)

messageId
string
threadId
string
providerMessageId
string
status
enum<string>
Available options:
pending,
sent,
failed