[Dovecot] Shared mailboxes (maildir, symlinks) and permissions

[Sergey A. Kobzar]

Hi Andreas,

Check mailing list archives. I asked same questions last week.


My Configuration:

mail_location = maildir:/home/mail/%d/%n
mail_extra_groups = mail

namespace public {
  separator = /
  prefix = Public/
  location = maildir:/home/mail/public
}

namespace private {
  separator = /
  prefix =
  inbox = yes
}

/home/mail/public/:
total 4
drwx------ 7 mail mail 208 Jul 24 10:25 .
drwx------ 4 mail root 104 Jul 24 10:18 ..
drwx------ 5 mail mail 296 Jul 24 10:52 .Non-Spam
drwx------ 5 mail mail 296 Jul 24 10:33 .Spam
drwx------ 2 mail mail  48 Jul 24 10:18 cur
drwx------ 2 mail mail  48 Jul 24 10:18 new
-rw------- 1 mail mail  14 Jul 24 10:25 subscriptions
drwx------ 2 mail mail  48 Jul 24 10:18 tmp

/home/mail/public/.Non-Spam:
total 28
drwx------ 5 mail mail   296 Jul 24 10:52 .
drwx------ 7 mail mail   208 Jul 24 10:25 ..
drwx------ 2 mail mail    48 Jul 24 10:52 cur
-rw------- 1 mail mail     0 Jul 24 10:13 dovecot-shared
-rw------- 1 mail mail    69 Jul 24 10:25 dovecot-uidlist
-rw------- 1 mail mail   144 Jul 24 10:52 dovecot.index
-rw------- 1 mail mail 16384 Jul 24 10:52 dovecot.index.cache
-rw------- 1 mail mail   460 Jul 24 10:52 dovecot.index.log
drwx------ 2 mail mail    48 Jul 24 10:25 new
drwx------ 2 mail mail    48 Jul 24 10:25 tmp

/home/mail/public/.Spam:
total 32
drwx------ 5 mail mail   296 Jul 24 10:33 .
drwx------ 7 mail mail   208 Jul 24 10:25 ..
drwx------ 2 mail mail    48 Jul 24 10:29 cur
-rw------- 1 mail mail     0 Jul 24 10:14 dovecot-shared
-rw------- 1 mail mail    62 Jul 24 10:25 dovecot-uidlist
-rw------- 1 mail mail   144 Jul 24 10:29 dovecot.index
-rw------- 1 mail mail 17408 Jul 24 10:29 dovecot.index.cache
-rw------- 1 mail mail   460 Jul 24 10:33 dovecot.index.log
drwx------ 2 mail mail    48 Jul 24 10:18 new
drwx------ 2 mail mail    48 Jul 24 10:25 tmp


Everything works nice.

BTW /home/mail/public/ is not a mailbox and must not contain cur new
and tmp folders. As Timo said this bug was fixed in 1.1.



Saturday, July 28, 2007, 5:11:05 AM, you wrote:

> Hello list, 

> I am trying to set up a public mailbox for users to put spam in so that
> sa-learn can do its job at night. Only I can't seem to fully understand how
> and which permissions should be set. I've read [1] and am using Dovecot
> 1.0.1.

> First some background information: I do not host or care (at the moment) about
> virtual users or virtual mail hosting. All users have Unix system accounts
> and shell access. I'd like to have a Spam folder, say /var/mail/public/.Spam
> that is a maildir where users can put Spam that got through the server-side
> filter. Spamassassin's sa-learn runs nightly and learns from the contents of
> the Spam folder.

> After reading [1] I think I should have under /var/mail/public a file called
> dovecot-shared that belongs to root:mail and has permissions 0660 (with user
> dovecot being a member of group mail) so that it looks like this:

> root at host:/var/mail/public# ls
> drwxr-sr-x 2 root mail 4096 2007-07-28 03:29 .
> drwxrwsr-x 3 root mail 4096 2007-07-28 02:19 ..
> -rw-rw---- 1 root mail    0 2007-07-28 02:46 dovecot-shared
> root at host:/var/mail/public#

> The first question arises: should Dovecot have write access 
> to /var/mail/public itself?

> Now I should create the Spam folder called /var/mail/public/.Spam. Should this
> directory be in maildir format, i.e. should it already contain the 
> subdirectories cur, tmp and new? What of the permissions of this directory? I
> am pretty sure Dovecot needs write access to it, so it should look like this:

> root at host:/var/mail/public# ls
> drwxr-sr-x 3 root mail 4096 2007-07-28 03:44 .
> drwxrwsr-x 3 root mail 4096 2007-07-28 02:19 ..
> -rw-rw---- 1 root mail    0 2007-07-28 02:46 dovecot-shared
> drwxrwsr-x 2 root mail 4096 2007-07-28 03:44 .Spam
> root at host:/var/mail/public#

> The .Spam directory here is completely empty.

> Now in a user's Maildir (/home/user1/Maildir) there are the user's private
> folders; a symlink to /var/mail/public/.Spam should be added:

> root at host:/home/user1/Maildir# ln -s /var/mail/public/.Spam .
> root at host:/home/user1/Maildir# ls
> ...
> drwx------  5 user1 user1 4096 2007-07-19 16:14 .INBOX.foo
> drwx------  5 user1 user1 4096 2007-07-06 23:01 .INBOX.bar
> ...
> lrwxrwxrwx  1 user1 user1  22 2007-07-28 03:51 .Spam -> /var/mail/public/.Spam
> ...
> root at host:/home/user1/Maildir#

> Is that all I have to do? Probably not, because I keep getting errors like the
> following when connecting (after subscribing of course):

> Jul 28 03:52:35 host dovecot: IMAP(user1): 
> mkdir(/home/user1/Maildir/.Spam/cur) failed: Permission denied

> Should I have created the cur, tmp and new subdirectories manually and set
> their permissions like /var/mail/public/.Spam? But that still wouldn't give
> user1 write access. If I gave the users (or "others": chmod o+w) write
> permissions then Dovecot's index files would be owned by the first user that
> connects to the server and uses that folder. Apparently also not a solution.
> I also don't think I should have to make my users members of the mail group,
> but I could be wrong here.

> So I am not sure what I am missing, or if what I want to do is at all possible
> (without taking out the sledgehammer and setting all permissions to 0777). I
> also apologise for this lengthy post with many details and little interesting
> questions. It's getting late and I fear I've reached a dead end.

> I'd really appreciate it if someone knowledgeable could point me in the right
> direction here.

> Thanks in advance!

> Andreas

> [1] http://wiki.dovecot.org/SharedMailboxes



-- 
Sergey