[imp] Validate Email Address

[Richard Carpenter]

Hello,

I would like to add validation of the To, Cc, and Bcc email addresses that
will prevent sending to email addresses that are clearly invalid.  To check
that the email address is at least something at domain.tld or
something at ipaddress.  Is there already something like this in IMP?  Where
would be a good place to add code for this validation?  I have looked at
/imp/compose.php and /imp/templates/compose/javascript.inc as possibilities.

Regards,
Richard