Cool Solution - How to separate IMAP server and OX App Suite
From Univention Wiki
This article describes how the separation of the IMAP server and OX App Suite for a mail domain can be configured, so both services can be run on different servers.
First of all you need two UCS systems. Let's assume they are named server01 and server02. For the UCS server role, choosing Domaincontroller Backup or Domaincontroller Slave is recommended.
On the first UCS (server01) please install the OX App Suite via the Univention App Center.
The installation will also configure a default mail domain according to your UCS domain name. Additional mail domains can be easily added using the UMC module OX E-Mail. The separation of the IMAP server needs to be configured for each mail domain separately.
To get a list of all mail domains managed by UCS, run the following command on the command line:
udm oxmail/oxdomain list
The output is similar to the following:
DN: cn=ox.example.org,cn=domain,cn=mail,dc=ox,dc=example,dc=org ARG: None oxImapServer: server01.ox.example.org oxContextName: context10 name: ox.example.org
Hint: Configuration is currently not possible using the UMC.
The important information is the field
oxImapServer, which indicates on which server the IMAP backend runs. Since UCS 4.0-3, this is Dovecot by default. If the server is now to be changed to a dedicated server running the IMAP backend, execute the following command:
udm oxmail/oxdomain modify \ --dn cn=ox.example.org,cn=domain,cn=mail,dc=ox,dc=example,dc=org \ --set oxImapServer="server02.ox.example.org"
Hint: Change server02.ox.example.org and the DN according to your needs.
Next, install the App "Mailserver" via the Univention App Center on the new IMAP server (server02).
Lastly the IMAP services can be deactivated on the server running the OX App Suite (server01).
systemctl stop dovecot.service dovecot.socket ucr set dovecot/autostart=no
Also, make sure that your IMAP server (server02) is set as "Mail home server" on your users.
There's an archived version of this article for UCS 4.0.