Started Jira 7.13.9 successfully , was able to define and test successfully POP / IMAP Mail Servers but when testing Mail Handlers, "No email in mailbox" was shown constantly (despite there were emails in the mailboxes).
Outgoing Mail configuration contains information it is disabled by default and this kind of information is missing in Incoming Mail configuration, so I was looking for other, possible, root causes the emails were not processed.
Once I restarted instance, with '-Datlassian.mail.fetchdisabled=false', emails were processed properly.
