Mike wrote in, and asked:
“Steve, We are working on a move from Exchange 2003 to a hosted Gmail solution. We will be using Outlook 2007 to access the Gmail accounts. I have not had much experience with Exchange 2003 – is there any way to convert those Exchange mailboxes to PST files without going to each account manually with the Outlook client?”
Very good question. That is one way to do it. You could login as each user, open outlook, and then export the users mailbox data to a PST file. Then you could use it for your Gmail IMAP account.
There is an easier way (Which is what you were hoping), since opening Outlook for each user could be very time consuming.
A free tool from Microsoft called ExMerge can do the trick.
To begin the export of your mailboxes, you will need to download it from here:
ExMerge Utility for Exchange 2003
Download the file, and execute it. The program will extract files from an archive.
You will need to get to your Exchange server, and place the files in this folder:
c:\Program Files\Exchsrvr\bin
From that folder, run the ExMerge.exe application.
Press next, and it will give you two options. We want the second option…since we are only pulling data out of the server:
Press next. It will ask if you want to extract, or import. Pick extract (option number 1):
Press Next and you will be asked for the server name. Enter the name, and press next (More than likely you will not need to enter the DC name, or an LDAP port number)
If you have more than one Exchange store, you can select it here. In my screen shot…I just have our main store.
Click next, and you will be shown a list of mailboxes. I blocked out my list since it is from a live server. Don’t want to publish names and account IDs:
Next you will be asked for a destination folder. This is where you can dump all of your PST files.
Click next, and it will start zooming through your mailboxes and create PST files for each account:
When it completes, you will have all of your accounts in PST form.
Now. How do you automate the creation of all those gmail imap accounts? Well that is for another article 
{ 3 comments… read them below or add one }
In my testing, it only appears to work for individual Exchange mailboxes that are 2GB or less. Can someone confirm this? If so, do you have any other suggestions for how one would break apart these larger stores? Thanks in advance.
Good catch. I just tried an export myself, and indeed it is limited to 2GB. Not sure if there is a workaround.
Another question is…does Outlook even support PST files over 2GB?
Yes, Outlook does support +2GB files. The only way I have found to get around it is by manually opening each users mailbox in Outlook, and then exporting it to a local PST file – painful, but the only way since ExMerge does not support +2GB files.