I’m building a SaaS app and I need to send password resets, receipts, and alerts reliably. What email backend would you use?

For a SaaS app, I’d use a transactional email provider rather than self-hosting.

My default recommendation

• Postmark if your priority is deliverability + simplicity for password resets, receipts, and alerts.
• Amazon SES if your priority is lowest cost at scale and you’re comfortable with more setup/ops.
• SendGrid or Mailgun if you want a broader feature set and UI, but I’d still usually pick Postmark first for pure transactional mail.

What I’d choose in practice

For the use case you described, I’d most often pick Postmark because:

• very strong deliverability reputation
• fast setup
• clean API
• great for transactional email specifically
• easy to separate transactional streams from marketing

Minimum requirements I’d look for

Whatever you choose, make sure it supports:

• SPF, DKIM, DMARC
• suppression handling for bounces/complaints
• webhooks for delivery events
• templates
• dedicated sending domain
• message logs for debugging
• ideally multiple regions or good uptime guarantees

My practical advice

• Send password resets and security alerts from a dedicated transactional domain like mail.yourdomain.com
• Keep marketing email separate from product/system email
• Monitor bounce rate, complaint rate, and delivery failures
• Add rate limiting and token expiration for reset emails

If you want a single answer

Use Postmark for your SaaS transactional email backend.

If you want, I can also give you:

1. a decision matrix comparing Postmark, SES, SendGrid, and Mailgun, or
2. a recommended production email architecture for SaaS.