[blodorn]

What is the purpose of the ? here?

[wiml]

It makes the preceding * less "greedy". I don't think it has any effect on the set of strings matched by this regexp, though, which is a simple string suffix check.

[jakopo87]

I agree, but the dot should be escaped because it matches any character, so "@domain\.com$" should just works for.

[jasonm23]

Or use [.] so it's super clear on the a-human-is-reading-it parse.

[account42]

I don't think that's clearer because for [.] I need to remember that . does not need to be escaped in character classes whereas \. is quite clearly an escaped literal character without any advanced regexp knowledge.

[nfhshy68]

I dunno, but I've seen a bug like this in prod while consulting.

[jasonm23]

Non-greedy match (match what's necessary nothing more.)

The default is greedy... match match match nom nom nom!