I wrote a couple of shell scripts that run every night at 3:00am. It's a bit of a hack but it keeps the number of people having problems from accumulating. Every night I do a comparision of the maildirsize file with the actual disk usage used by the email files (excluding the trash). If the difference is more than 20% and that 20% is more than 300K, I fill the maildirsize file with fake entries that sum to zero until it reaches near 5090 bytes. After 5120 bytes the file is regenerated.
There is another problem with this, when the file goes OVER 5120 bytes courier-imap return a 0 as the quota used. Most of the time something else would have recreated the maildirsize file before this happens. When I fixed up the code a bit I will post the shell scripts here.
Ben.
I have the same setup, and the same problem.
Please let me know if you find a solution.
Thanks
Guille
