I have this rather simple regex as an email filter:
.*@.*\.(?!(.*\.)?(com|net|org))
What it does is not match (not discard) any email with a top level domain of .com, .net, or .org. Example: jim@web.com will not match but jim@web.top will match.
This works 100% under CPanel but fails in Webuzo. It discards all email (matches) every time.
I believe the problem is Webuzo does not know know how to handle the negative lookaround (?!pattern).