Thanks to Wolfgang Ziegler (fago on Drupal.org and a Google Summer of Code for 2006), the feedback module was totally rewritten for 4.7.
The module now allows multiple feedback pages, each going to a different email address. It also has configurable categories.
The only thing that did not get carried over is the validation of the email address. The reason is that this feature was unreliable and slow since it involved opening a socket to the SMTP server for the domain, and trying to contact the user's email.
Several ISPs do not allow this including large ones like AOL and MSN. It also tied up a PHP process while slow socket operations happened.
If you relied on this feature, we would like to hear from you, and find ways for alternatives, e.g. patches for optional non-image captchas to lessen spam.