Skip to main content

SMTP

SMTP is the compatibility path for systems that already know how to hand mail to a relay. Use it for legacy applications, CMS plugins, CRMs, and servers where changing application code is harder than changing mail settings.

Relay settings​

Host: smtp.mtrgt.net
Port: 587
Encryption: STARTTLS
Username: smtp_mt_injection
Password: <api_key with Send via SMTP permission>

The username is fixed. The password is a Mailtarget API key with the SMTP permission scope.

When SMTP is the right path​

  • The application already has SMTP configuration fields.
  • You want to replace another relay without changing message generation code.
  • You do not need per-recipient substitution data or structured metadata at submit time.
  • You can handle delivery outcomes through webhooks or dashboard exports.

Use the API path when you need templates, attachments, metadata, or a structured response with transmissionId.

Production requirements​

  • Use a verified sending domain.
  • Enable STARTTLS.
  • Store the API key in a secret manager.
  • Keep SMTP credentials separate from API sending credentials.
  • Wire webhooks before using the relay for critical mail.