We are running Exchange 2003 Standard/Enterprise in several locations in the UK, and - a lot of the time - each site has their own DC and Exch server due to poor WAN links.
Now that WAN links are so cheap, we are looking to upgrade to to 100Mbs lines between each remote site and HQ. I also think we could bring back all mailboxes to our central Exchange Enterprise server in London.
HQ has about 1000 users, each remote site has about 100-500 users.
I was hoping for some expert advise on this;
a) Would it still be prudent to leave a DC in each remote site, or will this be unnecessary with the WAN upgrade?
b) What is the best way to calculate if we can fit the existing mailboxes onto our current HQ Exch server?
c) How would I carry out the mailbox moves, just using the Move Mailbox functionality in ADUC, or are there any special tools?
d) Is there anyway to calculate whether this will cause too much load on our HQ Exch server?
e) What is the recommended max number of mailboxes on an Exch 2003 server?