Validate email address in PHP [duplicate]

Question

Possible Duplicate:
How to validate an emailaddress in PHP

I was wondering what everyone is doing in regards to validating email addresses and how extensive the validation needs to be.

For example, of those methods, which one is preferred and why?

1. Extensive check: http://www.linuxjournal.com/article/9585?page=0,3
2. PHP filter: http://php.net/manual/en/filter.filters.validate.php
3. Eregi: http://www.totallyphp.co.uk/code/validate_an_email_address_using_regular_expressions.htm
4. Preg match with DNS check: http://www.soaptray.com/blog/2008/04/validate-email-addresses-using-php/

My goal is to find a good and solid solution for the average project, so when the time comes to validate an email address, I know exactly what I'm going to use.

Any feedback much appreciated!

-Ryan

Answer 1

Use PHP’s build-in filters for a syntactic validation and send a verification e-mail for an intention confirmation.

Answer 2

http://www.regular-expressions.info/email.html has the RFC2822 recommended reg ex.