Bird

Send Supabase Auth email with Bird SMTP

Use Bird SMTP to send the authentication emails your Supabase application creates. Supabase manages the templates and authentication links; Bird handles email submission and delivery reporting.

Before you start

  • Have permission to change your Supabase project's Auth settings.
  • Verify a sending domain in Bird and choose a From address on that domain.
  • Create a Bird API key with the emails scope. Use a separate key for this application so you can manage its SMTP settings independently.

Connect the SMTP service

  1. Open your project's Authentication settings and enable Custom SMTP. Supabase's SMTP configuration guide identifies the current settings location.
  2. Enter the sender name and your verified From address.
  3. Enter these connection values, selecting the host that matches your Bird key's region.
SettingValue
Hosteu1.smtp.bird.com for an EU key; us1.smtp.bird.com for a US key
Port465
Usernamebird
PasswordYour Bird API key
Port 465 uses implicit TLS. See the connection settings for the transport contract and supported alternatives.
Save the settings. Review your project's authentication rate limits and allowed redirect URLs before testing. In Bird's Email > SMTP settings, select this application's key and turn off click tracking for authentication email. This keeps sign-in URLs in the form generated by your authentication service. Keep the message category transactional.

Verify a complete sign-in

Use an address you control to request a confirmation or password-reset email from your application. Find the message in the Email log, check its recipient and delivery events, then follow its authentication link and verify the expected application screen.
A completed SMTP submission starts the delivery process. The email log and the completed sign-in establish the subsequent outcomes. Test the application's expiry and resend behavior separately before sending to customers.

Resolve setup failures

SymptomCheck
SMTP authentication failsMatch the key region to the host, use username bird, and check the key's email scope.
The sender is rejectedUse a From address on the verified domain in the same Bird workspace.
Supabase refuses another email requestInspect Supabase Auth logs and its configured rate limits.
Bird accepted the message but it is missingInspect recipient events, suppressions, and the receiving mailbox.
The email arrives but sign-in failsReview the Supabase redirect allowlist, link expiry, and application callback; check click tracking is disabled for this key.

Next steps