[Dovecot] Can I block dovecot from deleting read messages, after being fetched?

[Vasiliu Adrian]

Hi all,
Is there an option to disable (server-side) the deletion of read mails
after fetching them via POP3, regardless of the MUA config?

Here are the issues I'm facing:

   - my boss wants to force everyone into a server-side "no delete
   message"-policy, for archiving, auditing and backup&recovery purposes
   - the requisite here is pop3, so imap is out
   - the mailusers are virtual users (held in a mysql db)
   - don't have the budget to set up a separate mail-arvhing server
   - don't want to use shaggy ways (aka immutable flag, r/w permissions for
   Maildirs, etc)

dovecot --version
2.0.15

Help?
Thanks!