Migrating Rules From Microsoft Exchange to Google Apps

Recently I was part of transitioning the email system of a 20+ employee business off of a Microsoft Exchange 2003 server to Google Apps. Moving close to half a million emails to a new email service was a big decision. The transition tools that Google has in place are pretty good, albeit slow for that many emails, Google throttles email transfer to one each second after the first 500. However, the one piece that was missing was a good tool to transition outlook server rules. Many employees used those rules extensively and many had 50-100 rules. Outlook does not have any method in place for extracting those rules. There is no built in way to getting any sort of list or descriptions of the rules, if one wanted to transition the rules manually they would have to click on a rule, look at the pop-up window, and recreate the rules in Gmail using the filters functionality – repeating this two step process for each rule. Horrible.

This would waste many hours of valuable time so I started hunting for a better solution. There is an API in Outlook 2007 or higher that enabled access to rules. There isn’t much example code available, and to my surprise I couldn’t find any VB script to export a CSV of all the rules associated with an outlook account! I hacked together a really rough VB script which exports Outlook rules (only one rule type right now, thats all I needed for my use case) as a CSV and then wrote a small ruby script to generate a XML doc of the rules for import via Gmail’s import / export available through Gmail labs. It works fairly well assuming you have an updated version of Outlook 2007 or higher.

Google Apps Transition Notes

  • The server migration tool pulled in some calendar events that employees claimed they deleted long ago.
  • The Google Mail Uploader application for Mac is not consistent. It wouldn’t pickup mail on some computers. Doesn’t handle folder hierarchy (flattens everything). Use the server migration tool instead.
  • Mail.app folder doesn’t update folder’s unread count immediately. This might be an isolated issue with Lion.
  • I had a problem with one Mac machine (10.6) where the inbox would randomly appear blank. Clearing all Mail.app support / cache files and adding the mailbox with message + attachment cache disabled fixed the issue (after mail downloaded I enabled cache again).
  • Gmail doesn’t seem to handle lots of folders (labels) well. Mail.app seems to be a lot slower with multiple folders.
  • Hiding the automatic All Mail, Misc, Follow-up, etc folders was helpful for those who were not familiar with gmail.
  • Changing some of the local settings on Mail.app makes Gmail play a bit nicer.
  • Still can’t find a good solution to allowing a user that is an administrator of another user’s calendar to create an event with the organizer being marked as the calendar’s creator. Use case: administrative assistant managing an executive’s calendar.

2 Responses to “Migrating Rules From Microsoft Exchange to Google Apps”


  • As far as i could understand, you´ve posted in 2012 about an old Outlook version, that´s right? Does this VB script works with Outlook 2010?

  • That’s correct, the VB script does work with Outlook 2010 – although it doesn’t work with certain older versions without a specific patch (can’t remember the details of which update needed to be installed).

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