[Dovecot] Forcibly emptying a POP3 mailbox

[Răzvan Sandu]

Hello,


I've recently saw a discussion on this list, about a standardised way of
emptying POP3 mailboxes on the server - but no solution came up.


Please provide a suggestion for the following situation:

- I am running a stock POP3 dovecot server, on Fedora 12 (dovecot
version 1.2.9)

- passwd-file authentication via /etc/imap.passwd

- users are virtual, sharing the same UID/GID;

- storage is in MailDir system;

- for remote users, server is POP3-only, since the administrative policy
says that every user should download his messages on the local
workstation, then delete them from server immediately after succesful
download.

- IMAP is allowed only locally, in order to be used together via stock
squirrelmail Web interface (for emergencies only)


However, there are users that check the infamous „Leave a copy on the 
server” checkbox (or equivalent) in their mail clients, eventually 
adding „Delete messages after X days”.

Since I have no direct administrative control on the clients, I
absolutely need a way to forbid the above behaviour at server level, in 
order to enforce the policy. The server's HDD is meant to store received 
messages from reception to the first access only.

Filesystem quotas are not an option in this scenario, since the UID/GID 
is the same for all virtual users.

What I need is way to make sure that "cur" and "tmp" subdirectories are 
perfectly empty after the user downloads his mail.

(I will also need a way to make sure that users using squirrelmail leave 
no populated "Sent" and "Trash" folders on server's HDD, but that's 
offtopic here).


Could you please suggest a way to solve this ?


Thanks a lot,

Răzvan