You want the token [\[email protected]$]. Add to the ending + if you need it to match 1 or more times or a * if you need it to match 0 or more times.
\d is special and matches any digit character. Make sure that if you’re in a context where backslashes are being used for escape sequences (such as in a string) that you double the backslash.
http://regular-expressions.info/reference.html for more information