An email sent by a server administered by me bounced back saying it failed the SPF check. Looking at the bounce message it had an IP different to that of the server sending the email. Then I found that the message which was bounced was actually sent to a relay server of the recipient since the receiving server was down at that time. when relaying the server to the final server it refused the email.
Is this a normal behavior?
If I'm configuring a postfix server which has a relay server in case of a service failure, is there a way to stop this kind of behavior.