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 /v2/senders/, not /v2/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

Authorization	Bearer YOUR_API_KEY
Content-Type	application/json

Parameters

Field	Type	Required	Description
fromName	string	Required	Display name.
fromEmail	string	Required	Sending address.
smtpHost	string	Required	Must be a real, publicly-reachable mail server — private/internal addresses are rejected.
smtpPort	number	Required	SMTP port.
smtpUser	string	Required	SMTP username.
smtpPassword	string	Required	SMTP password.
imapHost, imapPort, imapUser, imapPassword	string	Optional	Enables native reply sync. If you send any one of these, all four are required.

curl -X POST "https://api.stynar.com/v2/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

Status	Code	Meaning
✕ 422 Unprocessable Entity	VALIDATION_FAILED	SMTP (or IMAP) verification failed — the error message says why (auth vs. connection).
✕ 403 Forbidden	QUOTA_EXCEEDED	You're at your plan's mailbox limit.
✕ 401 Unauthorized	UNAUTHORIZED	Missing, malformed, unknown, revoked, or expired key.
✕ 403 Forbidden	API_ACCESS_DISABLED	API access is turned off for your account.
✕ 403 Forbidden	INSUFFICIENT_SCOPE	The key doesn't have the scope this endpoint requires.
✕ 404 Not Found	NOT_FOUND	Unknown route, or a resource that doesn't exist / isn't yours.
✕ 409 Conflict	CONFLICT	The action can't be applied to the resource's current state.
✕ 429 Too Many Requests	RATE_LIMIT_EXCEEDED	Per-minute or per-second limit hit.
✕ 429 Too Many Requests	QUOTA_EXCEEDED	Monthly quota exhausted.
✕ 500 Internal Server Error	INTERNAL_ERROR	Something broke on Stynar's end.

Full error reference →

NextList senders