Office 365 data roaming explained

You might not even wonder where your data is located in Office365. It is linked to Azure location right? As it turns out, your Azure location has nothing to do with Office 365 data such as mailbox locations.

If you go to the Microsoft Office 365 trust center you can find a link to the Office365 article entitled ‘Where is my data?’. This takes you to a clear overview as to where your Office 365 tenant data may be stored physically. there are even data maps:

Let’s look at the data map that’s applicable for me, being the ‘Europe, Middle-East & Africa‘ one as I live in the Netherlands:

Europe, Middle-East & Africa data map for Office365
Europe, Middle-East & Africa data map for Office365

As you can see the Netherlands (encircled in green) has its own Office365 data center location, but in this region there are others as well. In addition, Microsoft has disclosed a list of data georedundancy for Office regions:

Regional datacenters
Regional datacenters

Last but not least, let’s look at Microsoft’s list of notes regarding the initial datacenter:
A datacenter is where the application software and customer data running on the software are located. For all customers located in a region, picking a region from the drop down box displays the locations of their datacenters and corresponding services. Microsoft replicates customer data in at least two datacenters at any given time to protect against failure or local disaster.

If a datacenter ceases functioning for any reason, customer data is not lost as the application software and customer data running on that application software are also available from a second or possibly third datacenter. Customers might not be notified when failover occurs. Depending on the particular service, failover may not result in any service interruption. Customers should assume that at any given time their customer data may be processed in either one or more of the datacenters in the region.

*If a customer accesses the online services portal from a region other than their own, then all viewed web pages will be hosted in that region’s datacenter.

**Long-standing online customer data is being migrated to new datacenters in accordance with these data maps however until the data migration is complete, long-standing customer data may be stored in other regional datacenters than is listed here.

***Azure Active Directory mentioned in the above data maps are instances of Azure Active Directory that hold directory data. A copy of directory data also exists in the relevant datacenters housing the Office 365 services.

This may (will) be really confusing for customers that already have an Azure tenant and configure its region to let’s say: West-Europe in my case. In addition, if they decide to link a new Office 365 tenant to it, you may be led to think that this data is, too, linked to West-Europe. This is 100% not the case (as I concluded in a discussion I had with a Microsoft TSP earlier). Your Azure data may be linked to West-Europe, while your Office365 data may roam throughout your entire data area.

There is a slight distinction that states that “active data is closest to your location and that data at rest roams throughout your data area”. For me, all my mailboxes were actively used, so the definition ‘data at rest’ may a bit confusing.

There is a script on Microsoft’s Scripting Gallery entitled ‘PowerShell Script to Determine Location of Mailboxes in Exchange Online‘ (get it here: This script is to be executed from an Exchange Online PowerShell session (follow these guidelines: In my case, the result showed the following:

Mailbox geographic data
Mailbox geographic data

Be sure to check out the Office 365 trust center regularly for updates!

One Comment
  1. Great article. Easy to follow. Now to figure out which mailboxes are where, and redistribute for better performance, as Finland is a long way from Dublin where all our users are.

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