It would be nice if JIRA was able to send out mails when new users sign up or are removed.

This is mostly useful for projects with many members where you need to assign groups to developers after they've signed up.

If the email could include links to the edit user / edit user groups pages it would be even more useful

UPDATE: This feature request should also cover when new users are created or removed by anyone in the application. It would be helpful as if a site has multiple site-admins, it would alert the others when a user is created, as well as if users are created via an external system import.