Moving Exchange 5.5

Well, there's no single answer to that question, but in my experience the method described here: http://www.swinc.com/resource/exch_faq_appxa.htm is by far the most reliable.

I've used it a number of times (heck, I helped edit the appendix) and it's been used by a lot of other folks in the past as well. There are other methods one could use (such as a backup and restore to new hardware), but in general the Ed Crowley Move Server method tends to have the least impact in terms of downtime andallows for staged moves if needed.

build second server out with operating system etc getting it to the same OS and Service Pack level along with any other post SP hot fixes, as the existing Exchange server, stop all exchange services on existing server, copy all *.edb's and logs to asecure location on the network, unplug from the network, delete from server manager for domains, plug in new server, rename new machine with old machines name joining the domain, setup new machine with old machine's IP address (key is to keep everything the same) install Exchange, apply service pack, rename *.edb files, copy old files to appropriate locations, restart services. if any problems arise you still have ALL mailboxes and data on the original server that is still running but is unplugged from the network.
any problems, unplug new server delete machine name from server manager recreate in server manager, give old box new name (SID's have changed), plug in to domain, and give it its original name back.