Correction: should read: However, if delivery is deferred to one recipient because of a lock failure (example follows) then the final line of the filter does not execute correctly, and more than one (perhaps all) recipients receive a message with an empty From: header.
Sorry for the confustion. Ken -----Original Message----- From: Ken Johnson [mailto:[email protected]] Sent: Thursday, April 22, 2021 4:14 PM To: '[email protected]' Subject: 'failed to lock' delivery deferral breaks system filter for me Exim 4.89 I manage the email server for a small company in the US. Less than 1000 received messages per day. A month or two ago I put in place a simple exim system filter that removes the 'Friendly Name' from the From: header. headers add "X-old-from: $header_from:" headers remove "From" headers add "From: <${address:$header_X-old-from:}>" This works well most of the time and has had good acceptance from the user community as part of anti-phishing efforts. However, if delivery is deferred to one recipient because of a lock failure (example follows) then the final line of the filter does not execute, and more than one (perhaps all) recipients receive a message with no From: header. The X-old-from: header does appear in the delivered message. ... defer (-9): failed to lock mailbox /var/mail/redacted (fcntl/flock) A pointer to a fix or workaround would be lovely; my current best alternative is to switch from mbox to maildir to reduce the frequency of delivery deferrals. Thanks. Ken -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
