All e-mail sent by Jamroom are controlled via the templates in the jamroom/templates/email/ directory.  These are full Jamroom templates, so you can use variable modifiers as well as template functions in your email templates.

On most Jamroom installs, the Email Templates can be edited directly from the Jamroom Tools -> Template Editor section, which gives you the added functionality of being abel to "search" through the email templates for text strings.