Use "mail.parse()" or whatever there is for your language. In general just parse stuff instead of letting some regexp loose on it.<p>For a quick check to make sure people don't mix up fields or accidentally hit enter before they finished typing, just /.+@.+\..{2,}/ is more than enough (technically foo@com is valid, but no one uses that – note that root@localhost or cron@sysops CAN be valid, so in some contexts you want to use just /.+@.+/, but that doesn't really apply for signups and the like).