How to Send Email in Supabase Edge Functions (SMTP & API)

Here is how to send email in Supabase Edge Functions so it actually reaches the inbox.

Your options in Supabase Edge Functions

Call an email API with fetch() from an edge function; keep your API key in secrets. (fetch() to an email API from an edge function.)

Make it land, not bounce

• Authenticate your domain with SPF, DKIM and DMARC.
• Send from a dedicated, warmed IP.
• Handle bounces and complaints via webhooks.

How Rainmail helps

Rainmail sends from your own domain on a dedicated, isolated IP with SPF, DKIM, DMARC, reverse-DNS and managed warm-up handled for you, plus a REST API and an AI watching deliverability — and it welcomes senders SES, SendGrid and Mailchimp reject, from $8. Run the free checker or see plans.