Global From Safe List exception

I have added *@mydomain.com in the global from-safe-list so that any emails from members of my company will be accepted.

Someone is spoofing us with a sender address of fax@mydomain.com and it is getting through even though it is spam.

Is there a way to add an exception for fax@mydomain.com but leave *@mydomain.com in the from-safe-list?

Cheers
David