JIRA's mail service (which processes incoming mails) should have the ability to ignore mail bounces, so that they do not result in new issues (and possible mail loops).

Of the jira-user bounces I receive:

• 75% have a Content-Type: multipart/report header
• 17% are from *mailer-daemon@'
• 8% are from majordomo, and the subject starts with "BOUNCE" (most people wouldn't get these).

Of bounces to personal mail, almost 100% are covered by the first two of these heuristics.

Almost none of these bounces have the Precedence: bulk header, which we added a check for in an attempt to avoid bounces.

So without going overboard and implementing a full mail filter in JIRA, I think we could identify most mail bounces with 2 simple hardcoded rules.