Send Mail API
Use POST /api/send to send email from your SipherMail account programmatically.
Endpoint
POST https://siphermail.com/api/sendRequest
Content-Type: application/json
Authorization: Bearer <token>
{
"to": "recipient@example.com",
"cc": "cc@example.com", // optional
"bcc": "bcc@example.com", // optional
"subject": "Hello from SipherMail",
"html": "<p>This is the <strong>HTML</strong> body.</p>",
"text": "This is the plain text body.", // optional fallback
"replyToUid": 12345, // optional: reply to this IMAP UID
"scheduledFor": "2026-06-01T09:00:00Z", // optional: ISO 8601 UTC
"fromEmail": "alias@yourcompany.com" // optional: for shared inboxes
}Response
// Success
{
"ok": true,
"messageId": "<unique-message-id@siphermail.com>",
"scheduledFor": null // or ISO 8601 if scheduled
}
// Error
{
"ok": false,
"error": "Recipient address is invalid"
}Field reference
| Field | Type | Required | Description |
|---|---|---|---|
| to | string | Yes | Recipient address. Comma-separate for multiple. |
| cc | string | No | CC recipients. |
| bcc | string | No | BCC recipients. |
| subject | string | Yes | Email subject line. |
| html | string | Yes | HTML body of the email. |
| text | string | No | Plain-text fallback body. |
| replyToUid | number | No | IMAP UID of the message being replied to. Sets In-Reply-To and References headers. |
| scheduledFor | string | No | ISO 8601 UTC timestamp to schedule delivery. |
| fromEmail | string | No | Send from a specific alias or shared inbox address. |
Attachments
Attachments via the API are not yet supported in this version. Upload attachments via the web or mobile compose interface.