We've been plagued with scammers using a form of CEO fraud. They are spoofing our Head of School. Emails are coming from HeadofSchoolemail@example.com where the ### can be any numbers or characters of any length. I can't block this address in the sender filter, so I'm assuming I need to use the content filter and filter on the heading? I cannot seem to figure out exactly what to use in this case. My attempts at creating a regex expression are not working. I've been banging my head on regex for hours. Can someone help me figure this out? I'm using Barracuda Spam & Virus Firewall 300.