What email provider should I use for auth emails?

For authentication emails like signup verification, password resets, and magic links, a good default choice is:

Best general pick: Postmark

• Very reliable for transactional email
• Strong deliverability
• Simple setup
• Great logs and message tracking
• Focused specifically on transactional email, not marketing

Good alternatives

SendGrid

• Widely used
• Flexible and powerful
• Better if you already use Twilio/SendGrid ecosystem
• Can feel more complex than Postmark

Amazon SES

• Very cheap at scale
• Solid deliverability if configured well
• Best if you’re comfortable with AWS
• More setup effort and less polished UX

Mailgun

• Good APIs and developer tools
• Common choice for app emails
• Pricing/support can vary depending on usage

If you want the simplest recommendation

• Start with Postmark
• Use Amazon SES if cost matters a lot at scale
• Use SendGrid if you want a broad, general-purpose platform

Important setup tips

No matter which provider you choose:

• Use a custom domain, e.g. mail.yourdomain.com
• Set up SPF, DKIM, and DMARC
• Send auth emails from a dedicated subdomain, like auth@yourdomain.com
• Don’t mix auth emails with marketing emails on the same stream if you can avoid it

If you want, I can also recommend the best provider based on your stack, budget, and expected email volume.