how can one override default registration email in a hook form alter registration?

Question

The main site sends a registration email and I do not want that email to be sent to this new registration as it should have its own custom email. I am having a hard time with this because every time a user registers either on main registration or this custom registration, they get the same mail. How can i keep my custom registration mail separate?

Answer 1

Simple way: http://drupal.org/project/advanced_mail_reroute

Answer 2

In the administrative interface, you can disable the feature to send email when a user registers. Then, you can just use drupal_mail() and hook_mail() to send your own custom email after the user has registered.

To do that, you will need to use hook_form_alter(), and alter the registration form to redirect to a custom menu callback. After you do that, you can send any email (or do anything else) you want.