Today I started looking at a problem that one of our staff was having after we finally found one customer with the same problem. Basically these users just "lost" their quota usage meter in squirrelmail. I'd put off looking at it since I thought it was probably an issue with the plugin - the plugin just sends an IMAP command to the IMAP server ("tag GETQUOTAROOT INBOX") and then parses the output, prints it in MB/% and draws a simple graph in the folder list frame.
However today I tried talking directly to the imap server (Courier IMAP 3.0.7) and found that it too was having issues reporting the quota:
a01 OK LOGIN Ok. a02 GETQUOTAROOT INBOX * QUOTAROOT "INBOX" "ROOT" * QUOTA "ROOT" <<<--- a02 OK GETQUOTAROOT Ok.
To contrast it with a "working" account:
a01 OK LOGIN Ok. a02 getquotaroot INBOX * QUOTAROOT "INBOX" "ROOT" * QUOTA "ROOT" (STORAGE 125149 307200) <<<--- a02 OK GETQUOTAROOT Ok.
Bear in mind that both accounts have quotas and vuserinfo (vpopmail 5.4.7) correctly reports the quota.
I dug through the Courier changelogs and saw no recent mention of any quota reporting issues.
I can temporarily "fix" this by deleting the maildirsize file in the user's Maildir. Is there some chance that vpopmail is straying a bit from maildir++ standards? Is there any way to debug this?