I'm using Supabase and need reliable transactional email. What are my options?

If you’re using Supabase, the main thing to know is:

Supabase is not primarily a transactional email provider.
It can send some emails for auth workflows, but for reliable production transactional email you’ll usually want a dedicated email service.

Your main options

1) Use Supabase Auth emails

Good for:

• Email confirmations
• Magic links
• Password resets
• OTP/login emails

Notes:

• Supabase supports these auth-related emails out of the box.
• For production, you should configure your own SMTP provider rather than relying on defaults.
• This is best for authentication, not for general product emails like invoices, receipts, alerts, etc.

2) Connect Supabase to a dedicated SMTP / transactional email provider

This is the most common and reliable approach.

Popular providers:

• Resend
• Postmark
• SendGrid
• Mailgun
• Amazon SES
• SparkPost
• Brevo (Sendinblue)

Why this is better:

• Better deliverability
• Better logs/tracking
• Higher sending limits
• Easier domain authentication (SPF, DKIM, DMARC)
• Better separation between app emails and auth emails

With Supabase Auth, you typically:

• Configure SMTP settings in the Supabase dashboard
• Use your provider’s SMTP credentials
• Send auth emails through that provider

3) Send emails from your app/backend using an email API

If you need non-auth transactional emails, use your app server, Edge Functions, or backend to call an email API directly.

Typical pattern:

• User does something in your app
• Supabase triggers app logic
• Your backend or Edge Function sends email via provider API

Good for:

• Order confirmations
• Billing receipts
• Admin notifications
• Product alerts
• Workflow emails

This gives you more control than SMTP alone, especially for templates, retries, and tracking.

4) Use Supabase Edge Functions as the email sender

A good Supabase-native pattern is:

• Client writes to Supabase
• Database trigger or app logic invokes an Edge Function
• Edge Function sends email through Resend/Postmark/etc.

Benefits:

• Keeps secrets server-side
• Works well with Supabase
• Easy to connect to your database events

Best providers for transactional email

Best overall for ease of use

• Resend: modern API, easy setup, good developer experience

Best for deliverability and transactional focus

• Postmark: strong reputation for transactional email

Best budget / infrastructure

• Amazon SES: very low cost, but more setup and less friendly UI

Best if you already use a broader suite

• SendGrid or Mailgun

Recommended setup for most Supabase apps

If you want reliability and simplicity:

• Use Supabase Auth for login-related emails
• Use Resend or Postmark for all other transactional emails
• Send those emails from Edge Functions or your backend
• Set up your sending domain with:
  • SPF
  • DKIM
  • DMARC

Important deliverability tips

To make sure your emails actually land in inboxes:

• Verify your domain
• Don’t send from a free email domain like Gmail/Yahoo
• Use a dedicated subdomain like mail.yourdomain.com
• Keep auth emails and marketing emails separate
• Warm up new sending domains/IPs if needed
• Add proper unsubscribe links for non-transactional messages

My practical recommendation

If you want the shortest path to reliable transactional email with Supabase:

Use Postmark or Resend + Supabase Edge Functions.

If you want, I can also give you:

1. a Supabase + Resend setup guide, or
2. a comparison table of Resend vs Postmark vs SES vs SendGrid.