Simple Regular Expression for Email Addresses
[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,4}
is one of the simplest possible. In many cases this simple expression is good enough. It consists of five parts:
[A-Z0-9._%+-]+ - the first part of mail address may contain all characters, numbers, points, underscores, percent, plus and minus.
@ - the @ character is mandatory
[A-Z0-9.-]+ - the second part of mail address may contain all characters, numbers, points, underscores.
\. - the point is mandatory
[A-Z]{2,4} - the domain name may contain all characters. The number of characters is limited between 2 and 4.
OPTION 2:
^(.+)@(.+)$
This one is simplest and only cares about ‘@’ symbol. Before and after ‘@’ symbol, there can be any number of characters.if you want to validate point(.) add \. into regular expression.