Notify non-jira E-Mail issue reporters about changes

[Pascal Kühne]

I've configured an incoming mail handler to create new issues for my project on incoming mail.
Since I am assuming I will get issue reports from a dozen different users, I can't create a new user per reporter since it would exceed my licence.
Is there a way to notify external reporter about changes to their issues? (Like issue was created, commented?)

[Pascal Kühne]

I just stumbled upon JETI (Email This Issue), it seems to solve the problem. Is there any way to do this out of the box? If not I'll try JETI.