wir möchten für unsere 2000 E-Mail Konten den bestehenden Mailserver auf Basis von iRedMail durch einen Univention Mailserver ersetzen. Ziel ist es für alle unseren bestehenden Benutzern, die auf mehrere Schulen aufgeteilt sind, einem zentralen Mailserver zur Verfügung zu stellen der über die UMC verwaltet werden kann. Um die Last im Netzwerk und unserem Master gering zu halten wäre es vermutlich am Sinnvollsten wenn der Univention Mailserver eine lokale Kopie vom LDAP hat. Deswegen stellt sich für uns die Frage welche Rolle der Server haben sollte.
Question:
What Would be the Best Way to Implement a Centralized Mailserver?
Environment
The queestion arises in a ucs@school environment where a centralized mailserver should be implemented for all schools with their OUs.
Discussion
Following implementations could be possible:
Option 1 - Mail server as member server w/o local LDAP
Disadvantage: All authentication requests will be forwarded to the backup or master which might lead to a high load on these servers
Advantage: Mail server can focus on his email tasks and no need to take care of LDAP synchronization
Option 2 - Mail server on ucs@school slave with creating a dummy ucs@school-OU
Disadvantage: Need to add all users to this OU. Might cause unforeseen issues.
Advantage: Server would have the needed LDAP data local and would not need to query other servers for authentication.
Option 3 - Mail server on a second backup server
Disadvantage: Without further configuration server would be included in LDAP synchronization. See here.
Advantage: Server would have the needed LDAP data local and would not query other servers for authentication.
Option 4 - Mail server on a slave server w/o ucs@school.
Disadvantage: As ucs@school get automatically installed (in ucs@school environments) make sure you uninstall the app and do not start the usc@school wizard. Thus, the slave will remain as a centralized server.
Advantage: Server can focus on his mail server tasks, does not forward authentication requests to other hosts and is not used as a a source LDAP synchronization.
Answer
Consider the above options and decide according to your needs and environment. Univention would suggest to select between options 3 or 4.