Package: fetchmail Version: 6.3.21-4 Hi. When fetchmail is unable to log into the IMAP server to fetch emails, it inject an email into the mail spool to report this problem. But the injected email lack message-id, causing the notmuch mail indexing system to not handle these emails very well. I discovered this when my scripts processing emails just failed to discover these when looping over all message-ids.
Here is an example email, with the complete header: From: [email protected] Date: Thu, 06 Feb 2014 14:52:47 +0100 (CET) MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="ISO-8859-1" Subject: fetchmail authentication failed on [email protected] Content-Length: 468 Fetchmail could not get mail from [email protected] The attempt to get authorization failed. This probably means your password is invalid, but some servers have other failure modes that fetchmail cannot distinguish from this because they don't send useful error messages on login failure. The fetchmail daemon will continue running and attempt to connect at each cycle. No future notifications will be sent until service is restored. -- The Fetchmail Daemon Please adjust fetchmail to include a unique message-id in these emails. -- Happy hacking Petter Reinholdtsen -- To UNSUBSCRIBE, email to [email protected] with a subject of "unsubscribe". Trouble? Contact [email protected]

