on 10-3-2008 11:44 AM jbdovecot@fcgh.net spake the following:
Hallo,
is it possible to implement a "flat folder view" for POP3 users?
The problem is that POP3 only knows one folder: INBOX. Now, if a user logs in via POP3, he won't see messages that live outside the INBOX folder - this could be e.g. a *SPAM*-flagged message moved to another folder via Sieve/LDA/other mechanism.
What about adding a feature
pop3_remap_foldersto virtually place *all* messages spread across different folders inside INBOX, only for the POP3 session, and without impact on the actual folder structure as seen thru IMAP?I see some issues though:
How would SENT and TRASH be handled? These special folders shouldn't be part of the game.
What happens if the POP3 client deletes a message, which is the default behavior of Outlook and friends? Proposed logic: really delete message if not logged in via IMAP since ($filemtime_of_message - $user_configurable_amount_of_seconds), else gracefully ignore client's delete request. This *could* become a problem if quotas are enabled, but then again it should be the admin's decision to offer this feature to his users.
Message IDs: Would the above Delete-only-if workaround confuse some mail clients and make them download the same messages over and over?
Perhaps another way: create a separate POP3 directory inside the mailbox, only used by dovecot-pop3. Inside reside symlinks to the actual messages spread across different IMAP folders, which can safely be deleted by a POP3 client and also following the real-delete logic described above.
The benefit of such a virtual folder remapping would be great for systems also using webmail and/or Sieve.
A pop3 user probably wouldn't be using any server side filtering. If you have mostly pop3 users you should be just adding headers or modifying the subject so they can client side filter them.
I don't think there should be any default server side filtering except for either tagging or deleting said flotsam. A user should be technically able to know how and what the filters are and how to use them, and be using IMAP if he wants server side filtering that moves mail around.
Besides what you propose probably violates a few RFC's.
-- MailScanner is like deodorant... You hope everybody uses it, and you notice quickly if they don't!!!!