[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.