Hi there, I am planning to install Exchange Server 2007 (evaluation) on my Windows Server 2008 box. The computer only has 1GB of DDR400 RAM but has a good CPU (P4 3GHz Prescott). I understand the recommended RAM size is upwards of 4GB but I would only have 3-5 mailboxes so it will be in a test environment. Would you say it should run fine on 1GB? Thank you very much in advance!

If all you're doing is playing around sure. I have many Exchange 2007 virtual machines that run with even less than 1GB. Recommendation is at least 2GB + mailbox cache per user, but again...if you're just wanting to play around go nuts...-alex

For a sandbox that would be fine. Technically you should have 1GB per core. For mailbox it is 2GB + 5mb per mailbox. What do you have for a DC? that will come in play as well being that Exchange 2007 is extermely AD intensive.SF - MCITP:EMA, MCTS

I agree, this would be ok for a test box but the performance you get will be poor. If I'm not mistaken Server 2008 recommends itself 2 GBs of memory. That is without Exchange on top of it. Mark Morowczynski|MCT| MCSE 2003:Messaging, Security|MCITP:ES, SA,EA|MCTS:Windows Mobile Admin|Security+|http://almostdailytech.com

Yes, it's OK for a lab, but it will be slow. Memory Minimum: 2gigabytes (GB) of RAM Recommended: 2GB of RAM per server plus 5megabytes (MB) of RAM per mailbox Minimum based on number of storage groups, see Planning Memory Configurations. This recommended memory configuration is suggested as a way to optimize performance for Exchange2007. Specifically, it allows Exchange to use an appropriately sized database cache, which reduces database disk input/output (I/O). These recommendations are oriented toward authorized production environments that have many users with large, frequently used mailboxes. Exchange 2007 System Requirementshttp://technet.microsoft.com/en-us/library/aa996719.aspx

Just wanted to post here that I installed and configured Exchange last night with 5 mailboxes and it's as spiffy as ever even under reasonable load. I might be able to score a retired Dell PowerEdge 1600 from work since we are doing the server roll-out soon. They were previously used in our datacenter as domain controllers and we are upgrading to Exchange 2007 soon from Domino Server so we are going to acquire new machines.

I would like to thank everyone who responded, you've given me a lot of information and I very much appreciate it.