Hello, I have an Exchange organization with 16 Exchange 2000 servers, a fewof which are deployed at sites with only a few users (some as low as 10). When the servers were put in (in 2001), Exchange and the current version of Outlook didn't handle the remote small office scenario very well, which forced us to install Exchange at the remote sites. We haven't bothered with an upgrade to Exchange 2003 (or Windows 2003 for the DCs) as we have been happy with the stability and functionality of 2000. However, I am now looking at what we would need to do for an Exchange 2007 upgrade. WhenExchange / Outlook 2003 were released, one of the selling points was improved support for remote installations (cached mode etc) and Microsoft have been pushing the idea of consolidating these remote servers back into a central site and have the users access their mailboxes in cached mode across the link. I was wondering what experiences people had had with this. I have no problem with the usability of cached mode accessing a remote mailbox under normal circumstances (I operate this way myself and have been very happy with it). I do have a few concerns with this setup though: 1. During the migration of a remote server to the central server, the mailboxes must be moved across the WAN link. Some of our users have rather large mailboxes (some up to 8GB), so this migration will take an extremely long time. If we neglect to setup the desktop for cached mode before the mailbox is moved (say a laptop is not available during the migration, or a user logs into 2 workstations and only tells us about 1 etc), it will need to be synced back over the link. 2. If the user's ost file becomes corrupt, or the Windows profile needs recreating for any reason, or the user upgrades their desktop, the mailbox will need to be synced over the WAN link again. 3. If a large attachment is sent to all (or many) users at a site, each user must pull the file over the WAN link. The users with the large mailboxes will of course be the biggest problem. Since the large mailbox users are generally senior staff members, they generally have the lowest tolerance for any kind of outage andscream the loudest. As I said before, I was just interested in other peoples experience with consolidating Exchange servers. Thanks Martin

Regarding your concern #1:We've never had any luck moving mailboxes greater than 1GB over a WAN-type connection (about 1.5mpbs in our case). The move always fails. For such a move, we've had to export the bulk of a user's mail to a pst, and then import the pst into the moved mailbox.

I am working in a large org which has same setup as you,lots of remote sites with single exch server and we migrated from 5.5 to 2003 a couple of years ago.We centralised all mailboxes back to corporate data centre on clustered servers.We centralised probably over 20000 mailboxes We did a lot of testing in remote sites as we also had a big concern regarding attachments being sent,cached mode etc. .We've had no problems with wan, large attachments did not have any significant/sometimes not even noticeableimpact on the links. We also had some very large mailboxes in sites with not so great wan links. What we did was shut down exchange and took an offline file copy of logs and databases and then just ftp'd the files back to corporate and did a restore to a 5.5 server there and then migrated to the new exchange 2003 server in the same data centre. Cached mode works well but as you said the downside is the usual first troubleshooting step of deleting profiles causing re-synch which can take time. hope this helps niamh