Why SPF Fails and How to Fix It

SPF fails when the sending mail server IP is not authorized in your domain’s SPF record. This often causes mail to land in spam or be rejected.

Common Causes

  • Missing sending provider in SPF
  • Wrong include: mechanism
  • DNS lookup limit exceeded (max 10)
  • Using -all too early while setup is incomplete

How to Fix SPF

  • Add the correct provider include (example: include:_spf.google.com)
  • Remove unused includes and flatten when needed
  • Keep total SPF lookups ≤ 10
  • Start with ~all (softfail) then move to -all when verified