Can you combine a regex lookup with another rule? That makes it an awful lot simpler. We have rules in Office 365 something like the following:

1. Address matches "first.?last", AND
2. Domain IS NOT "example.com"

(Watch out for inbound mail from users’ personal addresses if you do that, though.)

I don’t remember if the Barracudas can do compound rules. (Like stevieb, I used to admin Barracudas, but it’s been years.)

This really isn’t a Perl question, as such; Barracuda uses Perl-compatible regular expressions (as does Microsoft, for that matter), but unless something’s changed you can’t access the language from the admin interface. You might have better luck on a forum targeted more towards admins.

Update: Gah, it was stevieb who said he'd worked with Barracudas, not kcott.