First of all, I know that using regex for email is not recommended but I gotta test this out.
I have this regex:
\\b[A-Z0-9._%-]+@[A-Z0-9.-]+\\.[A-Z]
If you want to allow non-latain characters, this one works quite well for me.
"^[\\p{L}\\p{N}\\._%+-]+@[\\p{L}\\p{N}\\.\\-]+\\.[\\p{L}]{2,}$"
It does not allow IP's after the @ but most valid email in the from of xxx@xxx.TDL could be validated with it.
\p{L} validates UTF-Letters and \p{N} validates UTF-Numbers. You can check this doc for more information.