I beleieve that every information system has the needs to send emails.
Currently PostgreSQL doesn't have a function which gets TEXT and return true if it's valid email address (xxx@YYY.com / .co.ZZ)
Do you believe such function should exist in PostgreSQL or it's best to let every user to implement his own function?
There's a world of difference between an email address that is well-formed and one that actually works.
In the systems I administer there's a lot of time spent dealing with bounced mail to make sure that the email addresses we have actually reach someone, hopefully the intended target. And in the US, bulk emailers also have to deal with the CAN-SPAM act, which specifies procedures that must be in place to allow easy administrative options to remove one'e email address from mailing lists.
Procedures to verify that an email address works and to administer its use under rules like CAN_SPAM cannot exist solely within the database itself. And as others have noted, what makes for a 'well-formed' email address has always been a bit complicated.
