[Dovecot] Dovecot generate file when over quota detected

Hi,

I am curious if Dovecot can add an empty file into a Maildir folder as soon as a mailbox has exceeded 100% capacity, and later when it detects the quota has fallen below 100% unlink the file. The idea is the Dovecot LDA would deliver the message and if this caused the mailbox to reach 100%+, add a file into the maibox say "username/Maildir/overquota". Interactions via Dovecot IMAP/POP3 that lower the mailbox usage, for example the user popping, or deleting mail from the mailbox would trigger Dovecot to unlink the file.

This means that an MTA can efficiently check for the existence of this 'overquota' file and return a "user@domain.com Mailbox full" TEMPFAIL error early during the SMTP transaction prior to accepting any data.

Dominic