So the email handler is a bit lacking in functionality, at least if your customers also have their own ticket system.
Currently our customers can only reply based on email tickets, and thus we'd like them to be able to comment on issues simply based on the ticket ID in the subject of the email thread. Is this possible?
Right now I'm doing some weird hybrid where Service Desk itself handles creation of issues, and the Jira email handler handles commenting on issues, but it includes having our customers use 2 different email addresses.