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IMAP is touted as a more advanced protocol than POP, which is true in some regards, but in some scenarios it can be problematic (see link below). If you experience FolderClosedExceptions,FolderClosedException, which are due to your mailserver closing the connection on the mail being retrieved. Causes of FolderClosed include too many concurrent logins via multiple inbound mail server configurations for the same mailbox and mail that is too large for the default IMAP data batching data sizes used for retrieval. See the link below for some anecdotal performance results, and further details of what you can do to change your environment to work better with large mails over IMAP.
JEMH operates with a limited interface to Jira, we have raised this with Atlassian to improve their API, please watch/vote:
Message Removed
If you have concurrent access to a common mailbox its possible that a message may be 'removed' by another handler process, the error is likely to be harmless, unless the configuration caused the message to be dropped.
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