Basic Configuration
This page tells you the basics that you'll need to get a working Dovecot installation.
Find Dovecot configuration file location using:
dovecot -n | head -1
Your configuration file doesn't exist if you installed Dovecot from sources. Instead there's an example configuration file called dovecot-example.conf. You can use this as the base configuration file by renaming it:
mv /usr/local/etc/dovecot-example.conf /usr/local/etc/dovecot.conf
Authentication
Here we're going to create a simple passwd-like file to make sure that the authentication will work. Later when you know Dovecot is working, you can do it differently:
If you're going to use system users, see PAM.
If you're going to use virtual users, see VirtualUsers.
Run as your own non-root user:
echo "$USER:{PLAIN}password" > passwd.dovecot sudo mv passwd.dovecot /etc
You can (and should) replace the "password" with whatever password you wish to use, but don't use any important password here as we'll be logging in with insecure plaintext authentication until SSL is configured.
Now, configure Dovecot to use the file by modifying dovecot.conf:
auth default { .. passdb passwd-file { args = /etc/passwd.dovecot } ..
Also comment out passdb pam section so it's not tried unnecessarily. Verify with dovecot -n that the output looks like this:
... auth default: passdb: driver: passwd-file args: /etc/passwd.dovecot userdb: driver: passwd
Plaintext Authentication
Until SSL is configured, allow plaintext authentication. You probably want to switch this back to "yes" afterwards.
If you didn't use the temporary passwd-file created above, don't do this if you don't want your password to be sent in clear to network. Instead get SSL configuration working and connect to Dovecot only using SSL.
disable_plaintext_auth = no
Mail Location
Set the mail_location as instructed by FindMailLocation. (default_mail_env in older Dovecot versions)
mbox
If you're using mboxes, it's important to have locking configuration correct. See MboxLocking for more information.
If you're using /var/mail/ or /var/spool/mail/ directory for INBOXes, you may need to give Dovecot additional permissions so it can create dotlock files there. A failure to do so will result in errors like these:
open(/var/mail/.temp.host.1234.abcdefg) failed: Permission denied file_lock_dotlock() failed with mbox file /var/mail/user: Permission denied
From here on I'm assuming the INBOX directory is /var/mail.
First check what the permissions of /var/mail are:
# ls -ld /var/mail drwxrwxrwt 2 root mail 47 2006-01-07 20:44 /var/mail/
In this case everyone has write access there and the directory is marked sticky. This allows Dovecot to create the dotlock files, so you don't need to do anything.
# ls -ld /var/mail drwxrwxr-- 2 root mail 47 2006-01-07 20:44 /var/mail/
In this case only the root and the mail group has write permission to the directory. You'll need to give Dovecot's mail processes ability to use this group by changing dovecot.conf:
mail_privileged_group = mail
Note: Specifying the privileged user must be done as shown. Simply adding dovecot user to the mail group does not grant write permission.