Exchange Online|Office|Office 365

Microsoft Launches Workspaces, Then Pauses for Reflection

Microsoft dodged the opportunity to fire a bullet into their own foot when they pulled back plans to launch “workspaces” in Exchange Online. Announced on Monday and withdrawn on Tuesday, Workspaces are a new form of room mailboxes, the difference being that room mailboxes are used to reserve traditional conference rooms while workspaces seem to represent individual work areas like hot desks found in many office buildings. Microsoft says that a workspace is “a physical location where employees can work from. It can be made up of many desks or can be a single desk.”

Conference Rooms and Workspaces

Room mailboxes have attributes like capacity to help people schedule the right space for a meeting. It might have been possible to create workspaces using the existing room mailboxes, but Microsoft has opted for a modified version to handle different booking mechanisms.

For example, while conference rooms and workspaces both have capacities, the bookable capacity in a workspace is more granular (down to a single desk). In addition, workspace bookings are for a minimum of three hours to reflect the need of people to reserve space to use as a base when they check into a location. Apart from a different booking scheme based on workspace capacity, it should be as easy to reserve a workspace using Outlook as it is to reserve a conference room today.

Exchange and Custom Attributes

All of this sounds good. The problem is that Microsoft decided to hijack CustomAttribute11, one of the fifteen custom attributes available in Exchange Online, to distinguish conference room mailboxes and workspace mailboxes. These attributes were introduced in Exchange 2007 to give customers the ability to customize the settings of mail-enabled objects like mailboxes to meet business needs. For instance, some companies store a person’s office location code or department in a custom attribute and use it as the basis for filter to create dynamic distribution groups.

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Exchange Online supports fifteen single-value custom attributes and five multi-value custom attributes for mail-enabled objects, including the mailboxes used by Microsoft 365 Groups. These attributes can be synchronized with on-premises Exchange servers. The single-value attributes are especially useful because they support server-side filtering with PowerShell. For instance, if you stored office locations in CustomAttribute11 and wanted to find the people who work in Oslo, you could do something like:

Get-ExoMailbox -ResultSize Unlimited -RecipientTypeDetails UserMailbox -Filter {CustomAttribute11 -eq “Oslo”}

At least, you could, if Microsoft didn’t use CustomAttribute11 to identify workspaces. It was a curious decision because Microsoft has always made it quite clear that these attributes “aren’t used by any Exchange components.”

In this case, I imagine the engineers made the decision in a state of imperfect knowledge about the history and usage of the custom attributes. While regrettable, it’s easy to see why this might be so. No one knows everything about Exchange Online and some of its dusty corners store artifacts constructed long ago – like custom attributes, which were built to avoid the need for customers to extend the Active Directory schema.

Recipient Type Details Won’t Slow Things Down

To their credit, Microsoft recognized the problem quickly and regrouped to consider Plan B, which seems to be that they’ll use the RecipientTypeDetails property to identify workspaces. In other words, you’ll be able to do something like this to find workspaces in PowerShell:

Get-ExoMailbox -RecipientTypeDetails Workspace

It will take Microsoft some time to reengineer the change, but given that the required work doesn’t seem too extensive (add a new value for RecipientTypeDetails and update Outlook’s Room finder to find workspaces using RecipientTypeDetails), it shouldn’t take too long. Everything else to support the original launch for OWA soon followed by Outlook for Windows and Mac should just work, meaning that people might be able to book workspaces just about at the same time that they contemplate returning to offices.

All’s Well That Ends Well

People might be annoyed that Microsoft blundered into custom attributes with both feet. I take a different view. The right thing will be done in the end and this is a useful opportunity to remind tenant administrators about the usefulness of custom attributes. You never know when the availability of your very own attribute will make a difference in building a solution.


Tony Redmond has written thousands of articles about Microsoft technology since 1996. He covers Office 365 and associated technologies for and is also the lead author for the Office 365 for IT Pros eBook, updated monthly to keep pace with change in the cloud.
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