SMTP

Universal escape hatch. Works with Postmark, Brevo, your own Postfix, Gmail app passwords, and any other SMTP host.

Configure

Brand settings → Provider → pick SMTP. Fill in:

host — e.g. email-smtp.us-east-1.amazonaws.com
port — usually 587 (STARTTLS) or 465 (implicit TLS)
secure — true for 465, false for 587
user — SMTP username
pass — SMTP password (encrypted at rest)

Test connection

After saving, click Test connection. Maillayer opens a TCP connection, runs EHLO, authenticates, and reports success/failure.

Common providers via SMTP

Postmark: smtp.postmarkapp.com:587
Brevo (Sendinblue): smtp-relay.brevo.com:587
Resend: smtp.resend.com:465
Mailtrap (testing): sandbox.smtp.mailtrap.io:2525
Gmail: smtp.gmail.com:587 with an app password

Use the SMTP user, not your account email

SES, SendGrid, and Mailgun issue separate SMTP credentials in their dashboards. Don't use your console login.

Bounces & complaints

Pure SMTP doesn't deliver async bounce notifications back to Maillayer. If you need bounce/complaint handling, prefer the API-based providers (SES, SendGrid, Mailgun) — they POST events to /api/webhooks/<provider>/<brandId>.