I began having this trouble after upgrading from Lenny to Squeeze. In particular (summary from /var/log/apt/term.log):
courier-base 0.60.0-2 --> courier-base_0.65.0-3_i386.deb courier-imap 4.4.0-2 --> courier-imap_4.8.0-3_i386.deb libfam0 2.7.0-13.3+lenny1 --> libfam0_2.7.0-17_i386.deb I tried to replace fam with gamin, but the error for affected clients continued and additionally this made IMAP requests slow down to a crawl. Also we started to get the following errors in our mail.log: imapd: Failed to connect to socket /tmp/fam-- We determined the errors and imap slowdown came from gamin not liking our practice of using virtual users not in /etc/passwd, leading to mail folders owned by unnamed uid/gid pairs. Because of that every IMAP transaction had to time out talking to gamin before completing, making webmail almost unusable. We finally found relief from all of these errors by going back to fam, and by rolling back and pinning libfam0 (and thus fam as well) to 2.7.0-13.3+lenny1. This resolves the error even for courier 0.65.0-3 in squeeze, without having to change to gamin and without having to recompile courier to patch out fam dependencies (as I have heard other people online suggest). I'm pretty sure this even means the enhanced idle support will still work, though our users do not rely on that feature to my knowledge. Thus I surmise this is a new compatibility problem between courier and fam introduced by updates on the fam side somehow. :S I am a bug-report newbie so I don't know how or if to let the debian fam package maintainers know about the issue. But for users in the same boat as me, if you want to try my temporary workaround please follow the rough procedural guideline here: http://wiki.debian.org/RollbackUpdate check your /var/log/apt/term.log if you're not sure which version of fam worked for you before your update, and if you do see fit to roll all the way back to a lenny build like I did you might need to alter your apt sources file temporarily to "oldstable", apt-get update, rollback libfam0 (and thus fam), pin them in /etc/apt/preferences, change apt sources back to stable, and apt-get update again. You should only need to pin fam and libfam0, not courier or portmap or anything else. Stay safe! - - Jesse Thompson Webformix High Speed Internet http://www.webformix.com/