Reply to JIRA Service Desk notification creates a comment

Question

I have found numerous threads about this issue, however none of those answers worked for me as a solution.

We are using multiple request types in our service desk project.
We require our customers to login in to the portal in order to create a ticket in any category.
We would like to allow them to reply to email notification connected to this ticket which creates a comment in that specific issue. 
We also don't want them to create tickets via email - so therefore did not enable any email requests in our Service Desk project settings.

We would like to use the best practice for this configuration (without using things like Email this Issue plugin). Incoming Mail Handler does not seem to work properly. Any used / verified solution - step by step guide etc. ?

Thanks,

Matúš Klaudíny · Answer

Thank you for your solution. However, i think that such feature should work properly even without any additional apps.

Alex Christensen · Answer

You should be able to do this with the Enterprise Email Handler for Jira app. There's even this page in their docs that explains how to set some of this up in JEMH. I've also had really good experience with their support responses if you need additional help with set up.