Hi,

since I had no luck finding people available on IRC, I hope someone here can provide me with some answers to, hopefully, 2 simple questions (and have the solution recorded in the archives for everyone with the same need).

A little background, as the subject says it - I want to have a single INBOX shared among all the accounts on my system, where only one account would have writing rights, and all the rest would only be able to read the messages. Note this is different than providing a shared mailbox in addition to an INBOX - I actually want the shared INBOX to be the one and only folder that users can see and read as they will not be receiving any personal mails on this system. Naturally, I would also want that each account keeps track of read/unread messages independently of others.

So, this is what I came up with (showing the relevant part of configuration only):

# Per-user mail root and private/shared INBOX namespace userdb { driver = static args = uid=vmail gid=vmail home=/var/vmail/users/%u } namespace { type = private separator = / prefix = location = maildir:/var/vmail/public:INDEX=~/public inbox = yes }

# The ACL contents of /var/vmail/public/dovecot-acl user=admin lrwstipekx anyone lrs

Now, this actually results in exactly what I want (apart from a problem I'll describe below), but I'm not sure if it's the right way to do it. So the questions:

1. I have doubts that this solution could cause problems with dot file locking or dovecot data files corruption in the /var/vmail/public mailbox/directory when multiple users access the box simultaneously (and this could be thousands of users in production). Is this a valid concern and have I gone completely wrong with this solution, or there should be no problem with locking and I can keep it this way? If this is not the way to do it, can someone advise on the proper configuration that would achieve the same result, if it's possible at all (or what are the alternatives if it can't be done).
2. For testing purposes, I used a perl script (using the Maildir::Lite module) to create a test message in this mailbox (it gets stored in the new/ subdirectory, as I suppose it should). Now this message shows up as "unread" for all accounts, however when I read it in an IMAP client and then refresh the mailbox, it shows up as unread again. Per-user INDEX directory is writable and I see some files created there by dovecot, so shouldn't they contain the \Seen flags that indicate the message has been read? Is this maybe a client problem and how can I check that dovecot actually saves the flag correctly?

The dovecot version I'm using is 2.0.9 (from the CentOS 6.x repositories).

Thanks in advance and kind regards, Tin