Supabase Auth confirmation and magic link emails fail with Email address not authorized or hit a rate limit

Symptom

Email address not authorized when signing up anyone outside the project teamemail rate limit exceeded after two or three signups in an hourEmails reach team members but never real users

Cause

Without custom SMTP, Supabase sends only to members of the organization's team and caps sending at 2 messages per hour. After you add custom SMTP the cap starts at 30 per hour until you raise it.

Fix

Configure a custom SMTP provider before launch, then raise the email rate limit on the Auth rate limits page to match expected signups.

ApplyCopy

Dashboard: Authentication > Emails > SMTP Settings > Enable custom SMTP Dashboard: Authentication > Rate Limits > Rate limit for sending emails

Affected

Hosted Supabase projects using the built-in email service (no custom SMTP configured)

Sources

• https://supabase.com/docs/guides/auth/auth-smtp

Last verified 2026-10-15 · Confirmed by 0 builders