POST/v1/senders/

Connect sender

Connects an SMTP sending account — the same starting point as clicking “Connect Account” → SMTP in the app. The connection is verified live (Stynar actually logs in over SMTP, and IMAP too if you send those fields) before anything is saved, and credentials are encrypted at rest.

Stablescope: write API KeyLearn about API scopes →

Trailing slash required, and SMTP only

Call this as /v1/senders/, not /v1/senders. Outlook accounts aren't supported here — connecting Outlook requires signing into Microsoft in a browser, which doesn't fit a server-to-server API call, so that stays a dashboard-only flow.

Request

AuthorizationBearer YOUR_API_KEY
Content-Typeapplication/json

Parameters

FieldTypeRequiredDescription
fromNamestringRequiredDisplay name.
fromEmailstringRequiredSending address.
smtpHoststringRequiredMust be a real, publicly-reachable mail server — private/internal addresses are rejected.
smtpPortnumberRequiredSMTP port.
smtpUserstringRequiredSMTP username.
smtpPasswordstringRequiredSMTP password.
imapHost, imapPort, imapUser, imapPasswordstringOptionalEnables native reply sync. If you send any one of these, all four are required.
curl -X POST "https://api.stynar.com/v1/senders/" \
  -H "Authorization: Bearer esk_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"fromName":"Alex from Acme","fromEmail":"alex@yourdomain.com","smtpHost":"smtp.yourprovider.com","smtpPort":587,"smtpUser":"alex@yourdomain.com","smtpPassword":"your-smtp-password"}'

Response

201 Created
201 response
{
  "senderId": "sender_abc123",
  "fromName": "Alex from Acme",
  "fromEmail": "alex@yourdomain.com",
  "smtpHost": "smtp.yourprovider.com",
  "status": "VERIFIED",
  "imapConnected": false
}

Response fields

Errors

StatusCodeMeaning
422 Unprocessable EntityVALIDATION_FAILEDSMTP (or IMAP) verification failed — the error message says why (auth vs. connection).
403 ForbiddenAPI_ACCESS_DISABLEDYou're at your plan's mailbox limit.
401 UnauthorizedUNAUTHORIZEDMissing, malformed, unknown, revoked, or expired key.
403 ForbiddenAPI_ACCESS_DISABLEDYour account doesn't currently have API access.
403 ForbiddenINSUFFICIENT_SCOPEThe key doesn't have the scope this endpoint requires.
404 Not FoundNOT_FOUNDUnknown route, or a resource that doesn't exist / isn't yours.
409 ConflictCONFLICTThe action can't be applied to the resource's current state.
429 Too Many RequestsRATE_LIMIT_EXCEEDEDPer-minute or per-second limit hit.
429 Too Many RequestsQUOTA_EXCEEDEDMonthly quota exhausted.
500 Internal Server ErrorINTERNAL_ERRORSomething broke on Stynar's end.
Full error reference →