Migrate Microsoft 365 Exchange In-Place Archives to Gmail / Google Workspace

The In-Place Archive is Microsoft Exchange’s solution to long-term archival and storage of email data. The In-Place Archive does not count towards your main mailbox quota. However it can (on certain Microsoft 365 plans, most notably Exchange Online Plan 2) have an unlimited capacity for archived emails.

Email clients (apps or programs) such as Outlook, Thunderbird and Apple Mail do not attempt to download and cache the content of the In-Place Archive. This allows your main mailbox to remain nice and lightweight for the purposes of reliable syncing. But you can always search your In-Place Archive for historical emails if needed via a web browser or using newer versions of Microsoft Outlook.

For most users, we enable automatic archival of emails older than 2 or 3 years. Microsoft Exchange will recreate your existing email folder hierarchy inside the In-Place Archive (IPA) and automatically move any emails older than the threshold into the IPA for you. This is great for those users – you know who you are – with hundreds of thousands of unprocessed and un-filed emails in their inboxes. It stops their iPhone and PC or Mac from collapsing due to the effort of trying to sync a gazillion emails going back many years, but saves them having to actually tidy anything up themselves. Great!

Sometimes a business may choose to move to a new email platform. Probably the two major cloud business platforms at the moment are Microsoft 365 and Google Workspace. Both provide an email service which is the backbone of many other related services on their respective platforms.

Moving your business email to another provider is a relatively simple process on paper:

1. Choose your new email provider or cloud platform
2. Register your domain name with the new provider and set up mailboxes for all your staff
3. Use a tool such as MigrationWiz to move existing email data into the mailboxes at the new provider
4. Change the MX record in your domain’s DNS settings to begin routing email to the new provider
5. Run a final “delta” migration to transfer any emails that arrived between the first migration and the MX cutover
6. Reconfigure the email settings on your devices to point to the new email provider or cloud platform, instead of the old one

Microsoft store In-Place Archive email data in a unique way on the Exchange system to make it space-efficient. This means that In-Place Archives do not behave like an ordinary, live mailbox.

For this reason, you cannot use a standard email migration tool to access that archive data directly, in order to move the archived email across to a new platform such as Google Workspace.

To work around the problem of accessing In-Place Archive data in order to migrate it out, we can leverage a tool that Microsoft created to help businesses with in-house email servers (ironically) migrate into the Microsoft 365 cloud.

We’re also going to use Personal Store files, better known as PSTs, which is the file format used by Microsoft Outlook to store data on your PC.

Instructions for each part of the process are easily found using the links below. You can also refer to Microsoft’s knowledgebase and the documentation for your preferred email migration tool.

Here is the process for migrating your In-Place Archives from Microsoft 365 (Exchange Online) to Google Workspace (Gmail):

1. Using the Exchange Admin Console, make a list of all user mailboxes which have an In-Place Archive
2. Get hold of a Windows 10 PC running the latest version of Outlook (a spare workstation, or a virtual PC on a platform such as Amazon Web Services / EC2)
3. For each mailbox in turn, attach to Outlook then use the Export function to export the In-Place Archive to a local PST file
4. Check the size of the exported PST file against the reported In-Place Archive usage in the Exchange Admin Center, the PST should be marginally bigger than the In-Place Archive usage report, indicating that you have exported the entire Archive successfully
5. Use “network upload” with the AzCopy command line tool to transfer the PSTs back into Microsoft 365’s Azure storage
6. Set up a (free) shared mailbox in Exchange Online representing each In-Place Archive
7. In the Active Users list in the 365 Admin Centre, reset the password of all new shared mailboxes to a known value
8. Create a mapping file which will bulk-import all the exported PSTs into the new shared mailboxes
9. Use the “PST Import” tool under Information Governance > Import to bulk import your PSTs into the shared mailboxes
10. Finally, use your preferred email migration tool such as MigrationWiz to transfer the shared mailbox data into the corresponding user’s mailbox on your new email platform – you probably need to know the password of each shared mailbox to be able to do this, hence the need for step 6

We recommend, when importing the shared mailbox (In-Place Archive) data to your new platform, that you set the import parameters to migrate the data into a subfolder of the live account. This way, any import or export problems can be easily tried again by deleting the subfolder. You can then start over with no risk of messing up your live email folders on the new platform.