Some senders are getting the following return message:
Error transferring to mail.server.com; SMTP Protocol Returned a Permanent Error 550 5.7.1 Message rejected as spam by Content Filtering.
Content Filtering is currently set to Reject a SCL rating of 5 (tried dropping from a 6).
We have regular contact with several main companies. Is there a way to whitelist senders by domain? Is it efficient / effective? What kind of toll does it have on every message received?
I found and have tried using both of these in the exchange shell:
Set-ContentFilterConfig -BypassedSenders firstname.lastname@example.org,email@example.com
Set-ContentFilterConfig -BypassedSenderDomains example.com,foo.com
However, while this works for companies that have their own domain, what should be done for those that have emails with global providers? (comcast, sbcglobal, gmail, hotmail, etc.)
What direction should I take? Do I have something set up incorrectly / strict?