Hi, A strange problem has surfaced in my mail system, running postfix 2.6.6 on Red Hat EL 6. When an alias file has been updated, and postalias run, the system will incorrectly reject SOME (not all) mail with "User unknown" for a short while (a minute or so).
This only happens occasionally, and seemingly only if the alias update happens under fairly heavy load, while accepting many hundreds connections per minute. (On avarage, we deliver around 50 messages per minute.) The new alias file is written first to a temporary location, then moved into place, and then postalias is run. Postfix should not ever see incomplete data, which was my first suspicion. The temporary solution currently employed is to always change unknown_local_recipient_reject_code to 450 before alias files are updated. This system has been in use for a long time and no updates had been made recently at the time this was discovered. But the problem surfaces so rarely that the it might well have existed for a long time without anyone noticing. Anyone else seen this? -- Fredrik Sandström f...@abo.fi
