In /var/log/mail.log you see often the message:
Code:
SQUAT failed to open index file
SQUAT failed
This happes/means that the mailboxes/folders have no index. To solve this you need to run squatter.
Squatter is a part of cyrus.
The best position is in the /etc/cyrus.conf
Code:
EVENTS {
        # . . . .
        
        # add these lines in the part of EVENTS
        # running squatter
        squatter        cmd="squatter -r user" period=30
}
The squatter command will be executed by cyrus user. So be sure squatter is in the PATH
of cyrus or add the full path to squatter in the cmd.
Then it will look like this:
Code:
EVENTS {
        # . . . .
        
        # add these lines in the part of EVENTS
        # running squatter
        squatter        cmd="/usr/sbin/squatter -r user" period=30
}
-r means recursive for all subfolders.
user means all users.
period=30 means every 30 minutes execute the command.

Hope this help to solve this error.
I test this under Ubuntu "dapper drake" 6.06.2 LTS. So the PATH can be diferent on other distribution. You have to check it.