We have fully migrated to Exchange 2007 from 2003. This includes deleting the last Exchange 2003 machine form AD. Now the business wants to bring on Microsoft CRM 3.0. This requires an Exchange 2003 server to do the message tracking. We now need to install Exchange 2003. I am not sure about running the Domain and Forest prep for Exchange 2003. How can I install Exchange 2003.

Geoff, you already had an exchange 2003 server in the org. Running the 2003 domain and forest prep would not be good at this point. remember that because you upgraded your ORG from 2003, the attributes are there. If you did a new ORG, and didnt prep the domain with the 2003 attributes prior to going to 2007, ooops. you have an issue. Also remember that once the domain has been prepped and exchange 2007 server are in the org, you cant install and exchange 2003 server into the org again. So it seems that you have painted yourself into a corner. The next best solution would be to wait for CRM 4.0 to release, or depending on your org size, create a new org and migrate all users to that org, following the correct procedures. Here is a doc that lets you know what you are trying to do isnt supported. http://support.microsoft.com/default.aspx?scid=kb;en-us;937051&sd=rss&spid=1773 hope this helps.

It's either that or create a resource forest to support Exchange 2003, less that ideal but would allow you to move forward today. Erik

thanks all for the comments, they have been helpful Geoff

Thanks for all the comments they have been helpful

It was my understanding that when transitioning from 2003 and 2007, you can still install 2003 and 2007 servers into the org. Its only when its a brand spanking new exchange 2007 org than you can't do 2003. I know I have installed 2003 servers fine into my 2007 test lab.

NerdAlert! wrote: It was my understanding that when transitioning from 2003 and 2007, you can still install 2003 and 2007 servers into the org. Its only when its a brand spanking new exchange 2007 org than you can't do 2003. I know I have installed 2003 servers fine into my 2007 test lab. Is it than only if you try and do a 2003 /forestprep after 2007's /preparead that you run into the documentated issues? I've actually never tried it, as far as the OP may be worth discussing with PSS. Erik

You wouldn't ever need to. You might need to re-run domain prep for a brand new domain joined to the forest, you'd just run the legacypermissions switch then, but should all still be fine. I tired adding another 2003 server to my 2007 gig and worked a treat.

If you have already transitioned the org, and removed the last legacy exchange 2003 server, then tried to install an exchange 2003 server, that is when you would have the issues.

Correct Mark, That is the way it has happned and we did have issues. We have convinced the business -with the help from these post- to wait for the next version of CRM. Once again thanks to everybody for these GeofE

Geoff, I think that is a smart move. CRM version 4.0 (codenamed Titan) should be out soon enough. Glad that group was able to answer your questions and make the business make an educated decision. If you feel these posts were helpful, please mark them as helpful so others can search off of answered posts, thanks again again and good luck.