[Dovecot] maildir locking and 'racing'

[William Ross]

hello Timo, list,

quick error-message question. A few of the accounts on my main  
mailserver are failing to log in with errors like this:

dovecot: Mar 02 19:33:35 Error: imap(user at example.com):  
maildir_file_do(/var/lib/vpopmail/domains/example.com/user/Maildir)  
racing

if I log in by telnet everything is fine, and from the source it  
looks like the error happens when dovecot fails to get a lock on some  
important file or other. Could it be to do with concurrent  
connections? No idea. Has anyone seen this, and can you suggest a  
quick fix? I can't see any obvious difference between the accounts  
that work and those that don't :(

nb. this is with vpopmail, and the Maildirs have just been moved over  
from another server that was also running the same version of  
dovecot. Some of the accounts do work. Perhaps it's just an obscure  
file permissions problem, or something? I'd be very glad of any  
suggestions.

thank you,

will