My colleague Carsten released a new plugin today that adds a model
validation for email addresses.
It not only checks for well-formedness, but all checks that the
email's domain name is valid and has an MX record. This helps ensure
that fewer fake email addresses make their way into your database.
Should be useful to any app that has a User model with an email field.
(Aka, nearly all Rails apps.)
Blog post here: http://rails.savvica.com/2007/11/6/email-veracity-plugin
Kindly let us know if you have any trouble using the plugin. Really
looking forward to feedback.