I'm trying to do a Brand NEW deployment of exchange 2007 on a SINGLE server ( the domain has 2 other servers) the Exchange server has 4 xeon processors. currently 4 GB ram ( will upgrade to 8 GB) and 4 hdd ( 500 GB each) on a raid 5 configuration (Single drive 1.4 terrabite) I already created the first Partition c:/ = 142 GB ( for MS Server 2003 R2) here is the question. for a 50 userenvironment, what size should be my other partitions? log? and mailbox drives..?

I think you can put your C drive on RAID 1. Keep your logs on the same drive.Now for the DB , make it atleast RAID 5 (always recommended to have RAID 10).Now how big the D drive will depend on the size of the mail boxes, Dumpster, accepted growth rate etc,Try the calculator http://msexchangeteam.com/archive/2007/01/15/432207.aspxhttp://msexchangeteam.com/archive/2007/01/15/432207.aspxAs far as memory goes , ideally it should be 2 GB+ 5MB/Mail box. (http://technet.microsoft.com/en-us/library/bb738124.aspx)Raj