Email address with _ in LHS flagged as invalid

RT Users
1

We have a user who’s email address contains the underscore character in the
LHS. RT is incorrectly flagging this as an invalid address when I try to
modify it via the GUI. Could someone tell me where the regex that defines
what constitutes a valid email address is located so I can go modify it?

Thanks…

2

We have a user who’s email address contains the underscore character in the
LHS. RT is incorrectly flagging this as an invalid address when I try to
modify it via the GUI. Could someone tell me where the regex that defines
what constitutes a valid email address is located so I can go modify it?

I believe that in newer versions of RT the error message has been
improved to say “we already have a user with the address you’re trying
to change that to”