I've installed Windows Server 2003 R2 32bit on a virtual machine. From what I've read so far, it appears that there are two versions of Exchange available for 32 bit versions of Windows Server 2003: Exchange 2003 and Exchange 2007. I'd like to install Exchange 2007 (and test it). However Exchange 2007 is described as 'for non-production environments only' and I don't really know what that means. Does it mean that it is somehow crippled / not tested / has fewer features that Exchange 2007 64bit?
Or is is possible to perform migration to 64bit after installing Exchange 2007 32bit? I want to set a stable Exchange environment and play with it (with my mobile phone) for some time. Should I rather install Exchange 2003 or Exchange 2007?