I found a lot of Regex email validation in SO but I did not find any that will accept an empty string Is this possible through Regex only Accepting either empty string or email only I want to have this on Regex only

Regex empty string or email

This regex pattern will match an empty string:

^$

And this will match (crudely) an email or an empty string:

(^$|^.*@.*\..*$)

~ Answered on 2011-02-21 09:02:03