Set up SpamAssasin

# groupadd -g 5001 spamd
# useradd -u 5001 -g spamd -s /sbin/nologin -d /var/lib/spamassassin spamd
# mkdir /var/lib/spamassassin
# chown spamd:spamd /var/lib/spamassassin

To start the server in /etc/default/spamassassin set:

ENABLED=1

You can tweak SpamAssassin yourself in /etc/spamassassin/local.cf.

Set up vacation

The vacation script is a Perl script that will handle automtic replies when a user is out of office.

Copy scripts/vacation.pl to /var/spool/vacation/vacation.pl and edit the database connection properties.

# mkdir /var/spool/vacation
# useradd -r -d /var/spool/vmail -s /sbin/nologin -c "Virtual vacation" vacation
# chown -R vacation:vacation /var/spool/vacation/
# chmod 700 /var/spool/vacation/
# chmod 750 /var/spool/vacation/vacation.pl
# touch /var/log/vacation.log /var/log/vacation-debug.log
# chown vacation:vacation /var/log/vacation*

Create /etc/postfix/transport. Make sure the domain matches the postfixadmin_autoreply_domain you configured in the Group-Office config.php file before.

autoreply.example.com vacation:

Set up Dovecot

Dovecot is a fast IMAP deamon and it can also check user quota and filter Spam to the spam folder. Change / add these values to /etc/dovecot.conf:

#Enable IMAP and IMAPS
protocols = imap imaps 
#Listen on all IP addresses
listen = *
#configure the location of our virtual mailboxes
mail_location = maildir:/vmail/%d/%u
# Group to enable temporarily for privileged operations. Currently this is
# used only for creating mbox dotlock files when creation fails for INBOX.
# Typically this is set to "mail" to give access to /var/mail.
#mail_privileged_group =
mail_privileged_group = mail
# Grant access to these supplementary groups for mail processes. Typically
# these are used to set up access to shared mailboxes. Note that it may be
# dangerous to set these if users can create symlinks (e.g. if "mail" group is
# set here, ln -s /var/mail ~/mail/var could allow a user to delete others'
# mailboxes, or ln -s /secret/shared/box ~/mail/mybox would allow reading it).
mail_access_groups = mail
# Valid UID range for users, defaults to 500 and above. This is mostly
# to make sure that users can't log in as daemons or other system users.
# Note that denying root logins is hardcoded to dovecot binary and can't
# be done even if first_valid_uid is set to 0.
first_valid_uid = 150
last_valid_uid = 150

Inside the protocol imap { } section change:
mail_plugins = quota imap_quota
Inside the protocol lda { } section change:
postmaster_address = postmaster@intermesh.nl
mail_plugin_dir = /usr/lib/dovecot/modules/lda
mail_plugins = cmusieve quota
#the globalsieverc script will filter spam messages to the Spam folder 
global_script_path = /var/vmail/globalsieverc
Inside auth default { } section change:
auth default {
 mechanisms = plain
 passdb sql {
	 args = /etc/dovecot/dovecot-sql.conf
 }
 userdb sql {
	 args = /etc/dovecot/dovecot-sql.conf
 }
 user = nobody
 socket listen {
	 master {
	 path = /var/run/dovecot/auth-master
	 mode = 0660
	 user = vmail
	 group = mail
 }
 	client {
	 path = /var/spool/postfix/private/auth
	 mode = 0660
	 user = postfix
	 group = postfix
	}
}
plugin {
  quota = maildir:storage=512000
}

Also comment out the passdb pam section or you will get a very slow Dovecot connection!

/etc/postfix/dovecot-sql.conf:

driver = mysql
connect = host=localhost dbname=groupoffice user=vmail_user password=vmail_user_pass
default_pass_scheme = PLAIN-MD5
user_query = SELECT '/vmail/%d/%n' AS home, 'maildir:/vmail/%d/%n' AS mail, 150 AS uid, 8 AS gid, CONCAT('maildir:storage=', quota) AS quota FROM pa_mailboxes WHERE username = '%u' AND active = '1'
password_query = SELECT username AS user, password, '/vmail/%d/%n' AS userdb_home, 'maildir:/vmail/%d/%n' AS userdb_mail, 150 AS userdb_uid, 8 AS userdb_gid FROM pa_mailboxes WHERE username = '%u' AND active = '1'

Create globalsieverc script:

# mkdir /var/vmail/

Edit /var/vmail/globalsieverc:

require "fileinto";
if exists "X-Spam-Flag" {
  fileinto "Spam";
}

Set correct permissions:

# chown vmail:mail -R /var/vmail