Email “working” does not mean messages are actually reaching the inbox.
What to verify after migration
- SPF for approved senders
- DKIM signing for the domain
- DMARC policy and reports
- PTR for the mail server IP
Common mistakes
- Legacy SPF records with conflicting includes
- Missing DKIM after switching providers
- Sending from an IP without reverse DNS
Good practice
- Update DNS as part of the migration checklist
- Test delivery in Gmail and Outlook
- Avoid stacking unnecessary MX and SPF relays
Deliverability is infrastructure, not a minor item to postpone.