The journal task will run quite happily on the same server as other the other tasks, so you do not necessarily need another server. If you are looking at extremely large volumes of e-mail then you might want to consider it, though for the number of users you have specified it doesn't sound like that will be the case.

The Journal task shall work fine on the same EV server (subject to server H/W specifications).

Hi Jacques

 It would work but as mentioned  but what is the current utilization like on the EV server at the moment? Journaling is going to push the processor to probably 90 % so if the box is already battling that might be an issue. Even though the other tasks run in  the evening this is something you need to think of

Another consideration is what are you going to use to search against that Journal data ? I assume Discovery Accelerator as it comes bundled nowadays with the E-discovery and that also needs to be installed somewhere

In a small environment like that but with many different EV components  I would actually recommend an additional server running Journaling and DA on the same box .You can do your DA searches after hours when there is less Exchange traffic or just stop the Journal Task temporarily

Thanks for eveybody for these answers.

I think, I'll try to start jounaling archiving on the same EV server, and if there are some performances problems, I'll install a second one in a second time.

Kind regards