Make Dovecot Work for You

Installing dovecot on your personal ubuntu machine

arpepper@cscfpc20:~$ sudo apt-get install dovecot-imapd

Checking the version of dovecot you got

arpepper@dovecot:~ dovecot --version
1.2.9
arpepper@dovecot:~ 

Or you might need the following, or possibly even a variation.

arpepper@dovecot:~ /usr/sbin/dovecot --version
1.2.9
arpepper@dovecot:~ 

Versions of dovecot from ubuntu vary. With the introduction of dovecot 2.0 the syntax of the already arcane config files changed. dovecot 2.0 does not seem to have been packaged for ubuntu yet. Presumably because it would make so much documented stuff not work. Well, actually it might work, but would generate log file diagnostics indicating the new syntax which should be used. 19 Oct 2012 - ubuntu is now providing version 2, but I have not had the energy to change the tense of this entire page.

A major change affecting these examples is you must use

/usr/lib/dovecot/imap -c  ~/dovecot/dovecot.conf

in place of the old

/usr/sbin/dovecot -c ~/dovecot/dovecot.conf --exec-mail imap

Running Dovecot with Alternate Config Files

arpepper@cscfpc20:~$ sudo dovecot -c mypath/myconf.conf

E.g.

arpepper@cscfpc20:~$ sudo /usr/sbin/dovecot -c ~/dovecot/dovecot.conf

Running Dovecot Pre-authenticated

This use of dovecot is reasonably equivalent to the rimapd facility which used to be provided as part of older imap server software.

arpepper@cscfpc20:~$ /usr/sbin/dovecot --exec-mail imap

E.g.

arpepper@cscfpc20:~$ ssh -x dovecot.cscf -l arpepper /usr/sbin/dovecot --exec-mail imap
* PREAUTH [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT IDLE CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH] Logged in as arpepper
0 logout
* BYE Logging out
0 OK Logout completed.
arpepper@cscfpc20:~$ 

Or, use your own config file too...

arpepper@cscfpc20:~$ ssh -x dovecot.cscf.uwaterloo.ca -l arpepper /usr/sbin/dovecot -c /u/arpepper/dovecot.cscf/dovecot1.conf --exec-mail imap
* PREAUTH [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT IDLE CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH] Logged in as arpepper
0 logout
* BYE Logging out
0 OK Logout completed.
arpepper@cscfpc20:~$ 

If you are using dovecot 2, then you call the imap directly, instead of the above. See

arpepper@cscfpc20:~$ ssh -x dovecot.cscf -l arpepper /usr/lib/dovecot/imap -c /u/arpepper/dovecot.cscf/dovecot1.conf

You want to get your mail client, such as thunderbird, to talk to such sessions. mutt (Mail User Tool) can do that reasonably directly.

Running Dovecot as Localhost daemon only

Minimal dovecot.conf to use.

base_dir = /home/arpepper/var/run/dovecot1/
protocols = imap
listen = 127.0.0.1
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_location = mbox:~/mail:INBOX=~/inbox/%u
mail_privileged_group = mail
protocol imap {
}
protocol pop3 {
      pop3_uidl_format = %08Xu%08Xv
}
auth default {
      mechanisms = plain
      passdb pam {
      }
      userdb passwd {
      }
      user = root
}
dict {
}
plugin {
}

arpepper@cscfpc20:~$ sudo /usr/sbin/dovecot -c myconf.conf

Will start a server requiring authentication listening on the normal imap port on 127.0.0.1. You can create arbitrary such local servers for different purposes. E.g. 127.0.0.2, 127.0.0.3, etc. Or even addresses like 127.22.33.44. These will be accessible only to users logged on to the local machine, and will require authentication.

Using a mail client such as thunderbird you should now be able to add a mail account on server 127.0.0.1 or whatever you have chosen.

Multiple such private servers can be used to organize your mail in various ways.

For each such server you create, you need to specify a different /var/run directory, or confusion will result. The directories need to be created. To properly shutdown that daemon you could do something like...

arpepper@cscfpc20:~$ pf=/home/arpepper/var/run/dovecot1/master.pid
arpepper@cscfpc20:~$ sudo /sbin/start-stop-daemon --stop --quiet --pidfile $pf

Ideally you would create the directories somewhere which, like /var/run will be cleared at boot time.

Localhost Daemon without sudo

Minimal dovecot.conf to use.

protocols = imap
mail_location = mbox:~/mail:INBOX=~/inbox/%u
mail_privileged_group = mail
protocol imap {
}
auth default {
      mechanisms = plain
      passdb pam {
      }
      userdb passwd {
      }
      user = root
}
dict {
}
plugin {
}

arpepper@cscfpc20:~$ /usr/sbin/dovecot -c myconf.conf --exec-mail imap
* PREAUTH [CAPABILITY IMAP4rev1 SASL-IR SORT THREAD=REFERENCES MULTIAPPEND UNSELECT LITERAL+ IDLE CHILDREN NAMESPACE LOGIN-REFERRALS] Logged in as arpepper
0 logout
* BYE Logging out
0 OK Logout completed.
arpepper@cscfpc20:~/tmpdir$ 

That starts a pre-authenticated session on standard input. Note that at least some of the apparently null blocks are necessary in order to get imap protocol to work properly. The trick is to get a mail client such as thunderbird to talk to that.

If your machine has the socket command installed, you can use that.

arpepper@cscfpc20:~/tmpdir$ /usr/bin/socket -f -l -p '/usr/sbin/dovecot -c myconf.conf --exec-mail imap' -B 127.0.0.1 -s 14446

That command will sit there working as a daemon. You can then in thunderbird specify server 127.0.0.1 as an imap server, and afterwards go and change the port from 143 to 14446 (an arbitrary number; choose any one which is available).

The problem with that is that anyone who can sign on to your personal machine can connect to the service, and will be pre-authenticated as you.

If you don't have the socket command, you might be able to compile an equivalent from source. If you have sudo privileges, you are better to use sudo to start privileged daemons requiring authentication, rather than use sudo to install the socket command to later use non-sudo.

The socket command is a way, however, to gain access on your local machine to a mailbox on a remote machine to which you have indirect access. Once again, however, it leaves a localhost port open for pre-authenticated connection.

Useful variations on mail_location

Note that mail_location isn't exactly a variable name; mail_ is actually a prefix used to indicate that the variable location is set for the appropriate process.

Just mbox

• mail_location = mbox:~/mail:INBOX=/var/mail/%u

You can choose any directory to which you have access instead of ~/mail. It may also be useful to specify somewhere other than /var/mail/%u as inbox (to avoid altering possible actual inbox).

mbox inbox with maildir folders

• mail_location = maildir:~/.maildir:INBOX=/var/mail/%u

You can choose any directory to which you have access instead of ~/.maildir. It may also be useful to specify somewhere other than /var/mail/%u as inbox (to avoid altering possible actual inbox).

Note that the mail_location syntax does not let you specify one mbox directory and one maildir directory. But you could accomplish that by running two different dovecot servers on your own machine, or by using the imap namespace facility as implemented by dovecot.

Actually, it's worse than that. Many months ago my mind slipped up when I gave that faulty example. It actually expects a maildir structure beneath /var/mail/%u for each user.

To have an mbox INBOX and maildir folders, you must use namespaces.

Specifying Index Location

• mail_location = maildir:~/.maildir:INBOX=/var/mail/%u:INDEX=~/.indexes

Note that a directory structure will be created beneath there with directories named .imap created to house the actual indexes themselves.

Namespaces and User databases

base_dir = /home/arpepper/var/run/dovecot9/
protocols = imap
listen = 127.0.0.9
log_timestamp = "%Y-%m-%d %H:%M:%S "
mail_location = mbox:~/nomail:INBOX=~/nomail/%u
namespace private {
  inbox = yes
  hidden = no
  prefix =
}
namespace private {
  separator = /
  inbox = yes
  hidden = no
  prefix = "maildir/"
  location=maildir:~/.maildir
}
namespace private {
  separator = /
  inbox = no
  hidden = no
  prefix = "mbox/"
  location = mbox:~/mail:INDEX=~/.dovecot-indexes
}
protocol imap {
}
protocol pop3 {
  pop3_uidl_format = %08Xu%08Xv
}
auth default {
  mechanisms = plain
  passdb pam {
  }   
  userdb passwd-file {
    args = /home/arpepper/dovecot/dovecot9/passwdext
  }
  user = root
}
dict {
}
plugin {
} 

arpepper@cscfpc20:~$ cat /home/arpepper/dovecotdovecot9/passwdext
arpepper:x:1002:1002::/home/arpepper:/bin/bash:userdb_mail=mbox:~/my-mail:INBOX=/var/mail/%u:INDEX=~/.my-dovecot-indexes
arpepper@cscfpc20:~$ 

Timo once claimed to me you could have a userdb return namespaces, but he did not elaborate sufficiently for me work out how. Until that detail is determined, creating custom configurations which mix both maildir and mbox (which would seem to be desirable) would be problematic.

An "rimapd" approach is (almost) possible.

Silly mistakes that have wasted time for me

• Instead of INDEX I accidentally typed INDEXES (?!)
• INBOX=: instead of INBOX= gets errors trying to create null filename
  • (should be no ":" after =)
• Seems you need to exit and restart Thunderbird 3 before a newly-created folder is visible as a "copy" target in message selection area

Silly realities that weren't my mistakes that have wasted time for me

• cannot subscribe to top-level of a Maildir namespace
  • http://www.mail-archive.com/dovecot@dovecot.org/msg05329.html
• mbox namespace appears to need one folder pre-created?
• Thunderbird does not add newly-created folder to "Copy/Move message to" menu until after you exit and restart
• took a while to track down http://www.dovecot.org/list/dovecot/2010-November/054791.html

-- AdrianPepper - 15 Mar 2011
-- AdrianPepper - 19 Oct 2012
-- AdrianPepper - 20 Mar 2013