I'm sure this has been asked before, so please point me to the right post if need be. Basically I work at a software devolopment company that does some IT support and one of our customers has asked for our help on something and I want to make sure we don't get in over our heads.The situation is that they have a functioning 2003 SBS running Exchange 2003. They just bought 2 new Dell's running 2008 Standard. One is 64 -bit (the one that will be the Exchange Server) and one is 32 -bit. The old server and the 2 new ones are on different domains and will stay that way. Once the migration is done the old server will be taken offline. The goal is to get the mailboxes, public folders, distribution lists, etc onto the new server. They don't have that many users so a true "migration" may not be needed in the sense of moving Active Directory and the actual mailboxes. As long as we can get the data over to the new server everything will be fine. So my thought was either by using each users Outlook, or a tool on the server like Exmerge, we could get the data off in .pst files and then import them into 2007. I talked to a friend of mine that does this sort of thing regularly, and said he did a job like this back in Febuary and it was a nightmare. He said that Exmerge didn't work with 2007 and MS didn't support it. So my enthusiasm dropped right away I did see this article on Exmerg and 2007 so it seem possible: http://www.exchangeinbox.com/article.aspx?i=88.My friend also mentioned some differences about the way certificates were handled and needing two machines, one for webmail. and one autodiscover. each running IIS. Is this the case still? Anyway, I'm not asking for anyone to detail me out a step by step guide, although feel free if you are so inclined, but I just want to get some info before I dive into this thing. Thanks.

Adding Exchange 2007 to your SBS 2003 enviroment is easy. You should just move mailboxes. Rebuilding a forest is not necessary. Also, Exmerge has been replaced with import-mailbox, so you can just use that instead - but again, just add Exchange 2007, don't rebuild the forest. read here: http://www.msexchange.org/tutorials/Installing-Exchange-2007-Small-Business-Server-2003-domain-Part1.html http://www.msexchange.org/tutorials/Installing-Exchange-2007-Small-Business-Server-2003-domain-Part2.html

Issue description: We have two domains here [a.com; b.com], a.com has own exchange 2003, b.com will have own exchange 2007. Migration from a.com to b.com a. Install exchange 2007 on b.com b. Build trust between two domains c. Use ADMT v3.1 on windows server 2008 to migrate AD objects [keep SID History] d. Move Mailbox e. Migrate Public folders f. Remove exchange 2003 References: How to Transition from Single Forest to Cross-Forest Administering Domain and Forest Trusts