I began the uploading of our users old email in Outlook 2003 to Google Apps.
They have a lovely little program called Google Email Uploader that works with Outlook 2003 and newer, Outlook Express and Thunderbird that will upload your mail and contacts from Outlook to Google Apps. They also have a users guide here.
The progam works fine, however I did not anticipate the time that it would take to upload all of that information correctly into Google Apps. :-)
I started with the worse case scenario, the pastor with 25, 542 emails and 3079 contacts to upload. The estimated time for this is 8 hours. :-)
I had 3059 emails and the estimated time was 1 hour and 14 minutes.
I am going to migrate the rest in the evening, after they have gone home. Live and learn!