Ability to customize "Welcome to Aha!" email

Whenever a user is added to Aha!, the system generates and sends a “Welcome to Aha!” email; however, since we use single sign-on, the content contained in the welcome email does not apply to our users. This means I have to send my own email telling new users to disregard the Aha! email, and use mine instead.

As would be expected, users still try to click through the Aha! email, get an error message, then contact me and say they are having issues.

In order to avoid this duplication of effort, I would like the ability to either customize the Aha! welcome email with my own content, or have the ability to suspend this feature.