To enable / disable journaling for distribution list, login to the MSPControl and click on Distribution Lists,
or go to Organization > Exchange > Distribution Lists.
You will see all Distribution Lists. If you have many, it might be a good idea to use Search form in the right to find the one you need. You can choose whether you want to search by Display Name or E-mail Address.
Once you found the list you were looking for, select the list(s) you need by checking the corresponding check-boxes in the left.
Then select Journaling in the drop-down menu Actions, and click Apply.
In the new window check Enable Journaling, select a Journaling Rule to apply, decide whether you want to journal all messages, or only internal / external, and then click Ok.
To disable journaling simply un-check Enable Journaling check-box and click Ok.