Customized Web Signup Emails?

Is there a preexisting method for specifying different email templates depending upon the usergroup a user registers in (front end using Login and the backend when manually entering a new user)? Assuming not, I'm guessing a plugin will be necessary to achieve this ... using the OnUserActivate (front) and OnUserSave (back) events? If so, how do you override the use of the default email template?

I think you can specify your own email template as part of the Register snippet (see http://rtfm.modx.com/extras/revo/login/login.tutorials/login.request-membership) -- the Snippet has pre and post hooks available (see http://rtfm.modx.com/extras/revo/login/login.register) so you might be able to use those.

This does cover the activation email. For some reason, I also thought there was a post-activation email that go sent out too. At any rate, I assume for manually-created users, the email tpl would have to be chosen through a plugin, right?

For manually created and activated users, you can use the ActivationEmail extra and your own Tpl chunk.