[Dovecot] Dovecot - Issue with Maildir++ quotas

[Andrew Richards]

Hi,

I've been bitten by an issue running Squirrelmail on top of Dovecot 
using Maildir++ quotas.

Having configured these quotas in Dovecot, I notice that Dovecot 
appears not to exclude the 'Trash' folder from its quota calculation 
(which it should do, according to the Maildir++ spec). Unfortunately 
this breaks Squirrelmail if I try to delete a message from a 
close-to-quota mailbox - as per July's thread:
   "Maildir++ quota - how to handle a full mailbox"

Which unfortunately means that a fairly full mailbox can become 
'Wedged' with Dovecot/Squirrelmail in this situation with its owner 
unable to delete messages if that's the only way they access their 
mailbox.

I took a look at the source and found the 'Quota exceeded' lines in 
src/plugins/quota/quota-storage.c but didn't understand it well 
enough to dive in... except to notice that the 'Trash' folder doesn't 
appear to get excluded from the calculations.

cheers,

Andrew.