EAC Upgrade Distribution List Feature is Terrible

I met Tim McMichael at the recent TEC 2024 event in Dallas. Tim works for Microsoft as a senior escalation engineer. He’s the kind of person whom you don’t want to meet during a support incident because if you do, it means that you have a very sick Exchange environment. In any case, Tim also maintains an excellent utility for migrating on-premises distribution list to Exchange Online. The utility has been around for a while (I last mentioned it in 2018), which is testament to Microsoft’s (the engineering group) disinterest in this topic.

All of which brings me to MC510333 (last updated 27 April 2023), which describes the facility in the Exchange Admin Center to upgrade a distribution list to a Microsoft 365 group. I ignored this update for a long time, mostly because the feature took forever to arrive but also because it’s terrible. The feature never worked any of the times I’ve tried to use it. The documentation is also poor.

Testing the Upgrade Distribution List Feature

The upgrade distribution list feature works as follows:

An administrator initiates the upgrade by selecting the distribution list in the EAC and taking the Send upgrade request option (Figure 1).

Figure 1: The send upgrade request option in the Exchange admin center

The Send upgrade request action invokes a dialog (Figure 2) to send the upgrade request to the distribution list owners. Only one owner must be selected and EAC uses the signed-in user’s credentials to create and send the message from their mailbox. You can’t edit the message text, which seems like a missed opportunity to allow tenants to add their own information to the message.

The upgrade request duly arrives in the inbox of the selected recipients. The message content seems to be an adaptive card (Figure 3). Pressing the upgrade button starts a background process to upgrade the selected distribution list to a Microsoft 365 group. Microsoft says that this process should take no longer than 10 minutes.

In my experience, either nothing happens – even after hours of patient waiting – or an error is immediately detected and the adaptive card reports an upgrade process failure (Figure 4).

I’ve only ever attempted to upgrade distribution lists that meet the criteria (membership composed solely of user accounts and cloud-based). All of the distribution lists I tried to upgrade were in the set reported as eligible for upgrade by the Get-EligibleDistributionGroupForMigration cmdlet.

I also tried to upgrade distribution lists with the Upgrade-DistributionGroup cmdlet. Despite successfully submitting a distribution list to be upgraded, nothing happened and the same feeling of dealing with black box occurred. I suspect that Exchange Online invokes the cmdlet when a distribution list owner presses the Upgrade button in the adaptive card as described above.

Upgrade-DistributionGroup -DlIdentities Conference.Organizers@office365itpros.com

dlIdentity : Conference.Organizers@office365itpros.com
ErrorReason :
ExternalDirectoryObjectId : 58ad00b8-4800-48b9-b698-52467635ccf4
SuccessfullySubmittedForUpgrade : True
Identity :
IsValid : True
ObjectState : Changed

I never managed to convert a distribution list. Maybe the problem lies in the fact that my tenant is part of a multi-tenant organization (MTO). Perhaps having several fallback domains might affect the ability of the conversion process to work. But who knows? The lack of feedback and error messages makes any attempt to diagnose an exercise in guesswork.

Overall, the upgrade group type feature is the most frustrating part of EAC. It’s not helped by the paucity of documentation to describe what to do next (apart from contacting your administrator for assistance) when problems happen. The only page available cites reasons for upgrade failure like distribution lists with more than 100 owners or no owner. The page doesn’t cover problems upgrading a distribution list with one owner and three members, all of whom are user accounts in a cloud-only tenant.

Stay with Distribution Lists

Leaving the problems of the feature to one side, I do not recommend that organizations “upgrade” distribution lists to Microsoft 365 groups unless a solid technical and business reason dictates that the resources provisioned for a Microsoft 365 group are required. In many cases, the SharePoint Online site created for a distribution list when it’s upgraded to be a Microsoft 365 group is never used. The empty site takes some 60 MB of valuable SharePoint storage quota and clutters up the tenant.

Distribution lists that are used for email communication are more powerful in this respect than Microsoft 365 groups because they can include members other than user accounts, such as other distribution lists, mail users, mail contacts, public folders, and even Microsoft 365 groups. Ignore Microsoft’s silly recommendation that Microsoft 365 groups offer more collaboration tools (which are useless unless the tools are needed) and keep on using distribution lists the way they’ve always been used by email servers.

No One Uses the Upgrade Distribution List Feature

The current feature replaced a previous version that also had problems before Microsoft withdrew it from Exchange Online. I don’t know why upgrading a distribution list is such an intractable problem. Maybe Microsoft should ask Tim McMichael to fix the problems. At least he knows how to migrate stuff.

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