We have configured a SMTP server on IIS. We have not configured any SPF rule. Some emails are going straight to the badmail folder. Most of them have this error message:
Address does not pass the Sender Policy Framework
Is there any way to disable that? I know this is insecure and spammers could use it to send spam, but I really need it to be disabled for now until I have configured and tested the SPF correctly.
You can disable anti-spam filtering on the receive connector. console -> Org config -> Hub role -> Anti spam filter tab
The behaviour you are seeing is your receive connector checking that the people who send you a message have a valid spf record. There really shouldn't be anything to test. If a company is sending you email from a domain with an invalid spf record, then they will have problems with pretty much everyone, not just you.
That you have an spf record or not is of no consequence for messages that you receive.
