Question : Prep for new domain change

My clients are splitting their partnership so the company/domain name is changing. The current network is SBS2008 which is of course has exchange built in. What is best course of action to backup the mailboxes and sharepoint then move them to the new domain once it has been created. I know I cannot just rename the domain (sure would be nice to do that). The other issue is that the old email addresses have to remain active and forwarded to the new email addresses. I am thinking to just let the domain host (network solutions) forward the emails to the new mail boxes. I know I would also have to order new certificates for the server. I am looking for some suggestions on how to make this transition as smooth as possible. Not sure how to give points to this either, because I won't know which response worked until I have actually done it. It will be at least another month or two before this is to be done, I just want to be ready for that time.

Answer : Prep for new domain change

Before diving into the migration, is it absolutely necessary to do so? Just in case you are not aware, SBS can accept e-mail for multiple domains. The external domain names can change or you can have Exchange accept the mail for multiple domains. However you cannot change the internal domain name for logons and such. In many cases I find clients are willing to accept this as the set up is extremely easy and thus inexpensive.
If it is of some help to you:
http://sbs.seandaniel.com/2008/10/hosting-multiple-domains-on-sbs.html
Just food for thought.