Below is a more refined version. ^[-+.\w]{1,64}@[-.\w]{1,64}\.[-.\w]{2,6}$ Just as with the previous pattern, this one will match most valid e-mail addresses including:

• Addresses with periods and plus signs (e.g. ‘tiffany.brown’ or ‘hotc0derch1ck+todolist’)
• Top-level British and Australian domain names such as ‘.co.uk’ and ‘.com.au’
• New top-level domains such as ‘.museum’ and ‘.travel’

This pattern takes advantage of the \w character type. It’s a simpler way of waying “a - z (both upper and lower case), 0 - 9 and the underscore character” (though for many languages, \w means any alphanumeric character). It also checks to see whether a user or domain name contains at least one, but no more than 64 alphanumeric characters. Sixty-four is the maximum character length for user and domain names under SMTP. This pattern should work with most regular expression engines.