C# – case insensitive regex


I want to validate an email address with Regex in C#.

I'm using this pattern:


This pattern only matches upper case letters. For example:

"example@gmail.com" –> returns false.
"EXAMPLE@GMAIL.COM" –> returns true.

I obviously would like that the first example will also return true.

NOTE: I DON'T want to use the RegexOptions.IgnoreCase flag.

I would like to change the pattern itself to match the first example. I think that I can add a "/i" in the end of the pattern or something like this but it doesn't seems to work.
I prefer not to use the "?i" in the beginning as well.

How can i achieve this?

(If you could rewrite the whole pattern for me, it would be great!).


Best Solution

Instead of just [A-Z], use [A-Za-z].

But watch out: there are e-mail addresses that end in top-level domains like .travel, that are forbidden according to your regex!