I'm building an app that needs deliverability I can trust

If deliverability matters, you should optimize for a reliable email service/provider and proper authentication, not just “sending email.”

Here’s the practical checklist:

1) Use a reputable sending service

Pick a provider with strong infrastructure and good reputation, such as:

• Amazon SES
• Postmark
• SendGrid
• Mailgun
• SparkPost

For transactional email (password resets, receipts, alerts), Postmark and SES are often strong choices.

2) Authenticate your domain

Set up:

• SPF
• DKIM
• DMARC

This is essential for inbox placement and trust.

3) Send from a real domain

Avoid generic/free sender domains. Use:

• no-reply@yourdomain.com
• support@yourdomain.com

4) Separate transactional and marketing traffic

Use different:

• subdomains
• IP pools
• sender identities

This protects critical email from reputation damage.

5) Keep list hygiene strong

If you’re sending to users:

• remove hard bounces
• suppress repeat soft bounces
• honor unsubscribes quickly
• avoid purchased lists

6) Monitor reputation and delivery

Track:

• bounce rate
• complaint rate
• inbox placement
• spam folder placement
• open/click trends

7) Warm up gradually

If you’re sending from a new domain/IP:

• start with low volume
• increase slowly
• send to engaged users first

8) Make content trustworthy

Avoid spammy patterns:

• misleading subject lines
• URL shorteners
• excessive images
• too many links
• weird HTML or attachments

9) Handle bounces and complaints automatically

Your app should ingest provider webhooks and:

• mark invalid addresses
• stop sending to complainers
• retry transient failures carefully

10) Test before you rely on it

Use:

• seed accounts at major inbox providers
• tools like mail-tester
• provider deliverability dashboards

If you want, I can help you choose the best provider for your use case and give you a setup checklist for SPF/DKIM/DMARC.