Emails sending multiple times from Jira

[Jeffrey H]

We are experiencing an issue with Jira 6.3 where emails are sending multiple times. It happens during a certain workflow transition when an "Issue Stopped" notification is fired. I have scrubbed through the notifications, workflow, etc. and do not see anything that would cause the email to send multiple times. This does not happen every single time, some times it sends once, others twice, and some times as many as 5 times. I noticed that the message will sit in the mail queue highlighted in pink as if it's an error, but the notification continues to go out even while it's stuck, and then eventually clears. Any ideas?

[Matheus Fernandes]

Perhaps JIRA is having problems receiving the ACK from the mail server confirming that the email was sent, and therefore keeps sending the email - similarly to what's described in this doc.

Try checking the logs inside your jira-home/log folder (outgoing-mail.log) to see if there's anything there that could indicate why this may be happening. :)