Wietse Venema: > Your symptoms indicate a mis-match between the IN-MEMORY master > daemon process, and the ON-DISK executable files for smtpd, cleanup, > etc.
Famous last words. This may be the result of a Linux "misfeature" where a pipe inode number goes over 32bit: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=434851 Try this (with XXXX the master process PID): ls -l /proc/XXXX/fd | grep pipe If the number is >32bit like this: l-wx------ 1 root root 64 Jul 27 09:55 100 -> pipe:[4607501403] Then you need to recompile Postfix with "large file" support (or use a smaller file system). Wietse