Email

title: “Email” description: “Bring-your-own email provider setup, provider failover, and deliverability guidance” date: 2026-01-31 draft: false weight: 11

Email (BYO providers)

SendPromptly supports connecting your preferred email provider(s) for sending transactional messages (SMTP, SES, Mailgun, Postmark, Resend, etc.).

Add a provider

  1. In the portal, go to Provider Connections → Add Email Provider.
  2. Choose transport (SMTP, SES, Mailgun, Postmark, Resend) and enter credentials/API key.
  3. Optionally configure failover or round-robin providers.

Supported transports are defined in the app mail config: smtp, ses, mailgun, postmark, resend, sendmail, failover, roundrobin.

Health checks & testing

  • Portal runs provider health checks and shows connection status.
  • Use the Test Connection button to validate credentials and sending.

Template & payload limits

  • Email template output cap: 100KB. If a rendered template exceeds this size, delivery will fail.

Retry behavior

  • Email deliveries use the same retry schedule as webhooks: 0s, +1m, +10m, +1h, +6h (max 5 attempts).
  • Usage counters increment only once per delivery run upon the first successful attempt.

Failover

  • You can configure failover mailers (a failover or roundrobin mailer) to automatically switch or balance between providers when failures occur.

Example SMTP env vars (for self-hosted SMTP)

MAIL_MAILER=smtp
MAIL_HOST=smtp.example.com
MAIL_PORT=587
MAIL_USERNAME=your_user
MAIL_PASSWORD=your_password
MAIL_ENCRYPTION=tls
[email protected]
MAIL_FROM_NAME="Your App"

See portal Provider Connections for UI screenshots and exact field names.