Had no issues with Jira ServiceDesk for months. However last week our Exchange server decided to crash on the weekend and and had to be restarted. A day later on the Monday i noticed Exchange queues were stuck, so i restarted the services...
All ok for all users again, Except for emails into Jira.
Errors along the lines of multiple connection errors retrying in 1440 minutes etc...
So i migrated the mailbox to Exchange Online, Edited the incoming mail server with the new details and still nothing. (Logs didnt even show that it was trying to connect to outlook.office365.com)..
So deleted all the old incoming server, recreated it. and still nothing.
So deleted the mail handlers and recreated it, and still nothing. (It sees items, but thinks there is a loop and removes them)
And then deleted the "Email requests" email address for the service desk project. nothing fixed.
I'm now left with No Jira Service Desk-> Email requests Email addresses listed.
I have the incoming server setting in the Mail settings.
I have a Mail Handler "Create a new issue or add a comment to an existing issue" set with Create user ticked..
BUT it doesn't work.
If i Set a Default Reporter on that handler (to a JSD agent), then emails start coming in. ???
Any ideas on why it's so messed up now? How can i fix my mess 
Regards