Tips for Migrating from Exchange to Google Apps Gmail

I recently had the opportunity to migrate a client company's email system from Microsoft Exchange to Gmail within their new Google Apps account.
The company users love the Gmail email environment, and the company loves the cost savings gained by migrating from Exchange/Outlook to Gmail.

The biggest—but not only—challenges for this particular migration included overcoming connectivity issues with the Exchange installation.

Summary of key findings and recommendations:

1. The Migration Tool for Google Apps Migration for Microsoft Exchange and the Google Apps Sync for Microsoft Outlook plugin didn't run on Windows 7.
2. Despite reports to the contrary, the Migration Tool GUI worked fine (except on Windows 7), and you shouldn't need to run it from the command line.
3. You might need to run the Migration Tool on a server within the Exchange Server's network domain.
4. The actual migration process can take over 24 hours. Prepare your users, have them delete old email, and plan your time accordingly.
5. Using Outlook as a client for Gmail requires the use of the Google Apps Sync for Microsoft Outlook plugin. IMAP alone will not synchronize mail, calendar and contacts between Gmail and the local Outlook account.
6. For Outlook users, Google Apps Sync for Microsoft Outlook provides a setting to increase the default 1G Outlook mailbox size that it sets. You don't need to change registry settings.

The Migration Experience

As these things go, successfully executing the final migration process required research and some trial & error.

1. The first point of discovery was that I had to run the Migration Tool on Windows XP rather than my new Windows 7 installation. It simply wouldn't open in Windows 7 even in compatibility mode. It seems Google is always tweaking Google Apps, so I expect this will change.
    
2. While researching the Exchange connectivity issues I encountered with my local installation of the Migration Tool, I discovered more than one report that the Migration Tool GUI was flawed, and that you have to run it from the command line. This turned out not to be true, and running it from the command line did not resolve my connectivity issues.
   
   In this case, the connectivity issues were with the Exchange server environment itself. In the end, the Migration Tool GUI connected just fine to Exchange and to the Gmail account when it was installed and run on a server within the Exchange Server's local network domain.
    
3. The latter point is important. You may discover that even with the right connectivity information and the right user permissions, your local installation of the Migration Tool will not connect to the remote Exchange server. In my instance, firewall issues on the Exchange server's local network domain provided one of the the connectivity hurdles.
    
   In the end, it was easier to have the system administrator install the Migration Tool on a server within the Exchange server's local area network and to give me permissions to run it there using Remote Desktop Connection rather than to resolve the inbound firewall issues.
    
4. The migration process takes a really long time.
    
   The Migration Tool is multi-threaded to migrate multiple accounts simultaneously. For each account, however, it is configured to transfer only one item per second. One user account, representing 3G of data, took 18 hours to migrate.
    
   In order to reduce required migration time, ask your Exchange users to delete all old email they don't need. That includes deleting messages from the Outlook Sent Items folder, and it especially means—as the last step—deleting messages from the Deleted Items folder itself.
    
   Plan your personal time to conduct and monitor an overnight migration.
    
5. If a user wants to continue using Outlook as their mail client, you'll need to set up a new Outlook account for that user on their local machine, and you'll need to install the Google Apps Sync for Microsoft Outlook plugin.
    
   After a user's data has been migrated to Gmail, then Google Apps Sync for Microsoft Outlook will transfer a copy of each item in the user's new Gmail account to their new Outlook account. This was the user with the 3G mailbox. We started the initial Gmail-to-Outlook sync process at 5pm, and it completed around 9pm. Again, plan your time accordingly.
    
6. Google Apps Sync for Microsoft Outlook sets a default 1G size limit on the Outlook mailbox. Since 3G is greater than 1G, older messages did not get copied to the local Outlook mailbox until it was increased in size.
    
   To increase the Outlook mailbox size, right-click on Google Apps Sync in the system tray and select "Set mailbox size limit". Ignore recommendations you may find for changing registry settings directly. That didn't accomplish anything.
    
   The sync process is initiated every time you open Outlook, so once the mailbox size was increased the issue resolved itself.

Conclusion:

The huge advantages of migrating to Google Apps Gmail are the elimination of costs involved in administering Exchange Server and individual Outlook software installations, and elimination of the cost of hardware ownership.

Gmail provides a different user experience than Outlook, but the user acceptance level with Gmail was very high once the users understood the differences and recognized the advantages of the Gmail interface.

If you yourself are an Outlook user, I highly recommend conducting a migration of your own email data to Gmail in order to fully understand the process and to understand how your users will experience the change.

Resources:

• Google Apps Migration for Microsoft Exchange Administration Guide
• Migration Tool for Google Apps Migration for Microsoft Exchange
• Google Apps Sync for Microsoft Outlook