Is there any place in particular to find out about the theory and operation of lock files and the various mail processors used by Mandrake? Without having done the builds myself, it's not entirely clear what's been shipped. >From the source code, it appears that: procmail is configured to use dot locking, and explicitly disallows use of flock, lockf mailx is configured to use flock, and there's code included to disable use of dot locking nmh is configured to use fcntl locking, and to disable use of dot locking imap/pop3 is configured to use flock and dot locking The only extended discussion of email file locking I've found is in the imap/docs directory, in which Mark Crispin has a wonderful discussion of the topic. But as it stands, it appears that the "as shipped" configuration won't play together....