Add “Send Test Email” Button for SMTP Settings

Hello Supabase Team,

I’d like to suggest a small but very helpful feature:
Please add a “Send Test Email” button to the Authentication → Emails → SMTP Settings section.

This button would allow users to quickly verify that their custom SMTP configuration (host, port, credentials, sender address) is working correctly by sending a test email to a chosen address.

Why it matters:
• It helps avoid silent failures when setting up custom SMTP for password recovery, magic links, and verification emails.
• It saves time debugging email delivery issues without needing to trigger real auth flows (e.g. password reset).
• Currently, we have to manually test using supabase.auth.resetPasswordForEmail() and check logs, which is inefficient.

A simple form field to enter a test recipient + a “Send Test Email” button would improve the developer experience significantly.

Thank you for considering this improvement!

Best regards,
Alex