I don't think this will work. If you follow the RFC completely an e-mail "text space\@moretext"@host.com is valid, as well.
Some services have two input fields for an e-mail address. The second is to verify for typos. After that, just send the e-mail, already. If it fails you can delete the user entry from your database and print out something in the likes of "Who types their e-mail wrong two times?".
Some services have two input fields for an e-mail address. The second is to verify for typos. After that, just send the e-mail, already. If it fails you can delete the user entry from your database and print out something in the likes of "Who types their e-mail wrong two times?".