All you need for validating emails
regexlib.com
regexlib.com
http://www.regular-expressions.info/email.html http://search.cpan.org/~rjbs/Email-Address-1.889/lib/Email/A...
If I don't want you to have my email address, you'll get n.o.thanks@microsoft.com and that will fly through any shape validation, domain validation, character checks, any regex you can think of.
It still wont be my email address. If people aren't giving you valid email addresses, reassess your site and consider why instead of throwing technology at the alleged problem.