Fix "email rate limit exceeded" with custom SMTP | Vovy

My signup emails stopped sending, hook Supabase up to Resend

How it works

1. Add your domain in Resend: Vovy adds your domain under Domains in Resend and shows the DNS records it needs: SPF and DKIM, which prove to Gmail that emails really come from you.
2. Add the DNS records: It adds the records in your DNS provider, like Cloudflare, and waits for Resend to show Verified.
3. Create an API key for sending: Vovy creates a Sending access key in Resend. It becomes the SMTP password, so it goes straight into Supabase and nowhere else.
4. Turn on custom SMTP in Supabase: In Authentication, Emails, SMTP Settings it enters host smtp.resend.com, port 465, username resend, your key, and a sender like hello@yourdomain.com.
5. Raise the email rate limit: Vovy opens Authentication, Rate Limits and raises emails per hour from the starting 30 to fit your traffic.
6. Send a test signup: It signs up a test address and shows a card with delivery status from Resend's Emails log.

What you provide

• A domain you own
• A Resend account
• Access to your DNS provider

What you get

• Auth emails from your own address
• Verified SPF and DKIM
• A higher email rate limit
• A delivery log you can check

FAQ

Related tasks

• Stop bots from flooding my signups
• Fix login emails that send users to localhost
• Make users confirm their email before they get in
• Take my Clerk login from development to production
• Invite people to my app by email
• Set up email DNS so my emails don't hit spam