A short blog on something which I find still surprises admins and consultants working with Exchange Online Management module for Powershell. The Exchange Online Management v2 module has been offering support for REST for a while now. One of the benefits of using these REST-based cmdlets, apart from performance and resilience, is that it uses Modern Authentication to connect to Exchange Online, which is the way forward, as Basic Authentication gets directed to the exit.

Now the initial versions of the module supported a limited set of 9 cmdlets. The REST cmdlets used the EXO prefix, such as Get-EXOMailbox as counterpart of Get-Mailbox. I wrote an earlier blog about using EXOv2, configuring the app in Azure and alternative ways to authenticate here.

Per version 2.0.6, which is still in preview, around 250 additional cmdlets got REST support as well, but using their original name and parameter set. You can check the number of cmdlets available after connecting, e.g.

Install-Module ExchangeOnlineManagement
Connect-ExchangeOnline -UserPrincipalName <UPN>
((Get-Module).Where{ $_.ExportedCommands.'Get-Mailbox'} | Select-Object -ExpandProperty ExportedCommands).GetEnumerator() | Measure-Object

As you can see above, after connecting this version supports 397 cmdlets for my role in addition to the 31 available pre-connecting. Your exact number might vary, based on the roles assigned to your account.

The confusion usually starts when people enter commands or run scripts, and find cmdlets are “missing”. Often they find that the Set/New cmdlet is unavailable, while the Get is available, e.g.

Before, this could be an indication those commands were removed from the role assigned to you, such as the New-MailboxImportRequest cmdlet which only is available if you have mailbox import/export assigned. But in this situation, it could be that the cmdlet does not have a REST call (yet). In those cases, you need to connect using a regular Remote PowerShell session, by specifying -UseRPSSession:

Connect-ExchangeOnline -UserPrincipalName <UPN> -UseRPSSession

When connecting this way, I have 739 cmdlets at my disposal, including the ones which do not support REST. Note that cmdlets which support REST still will use REST; the commands that require Remote PowerShell will use the imported cmdlet. As a reminder, Remote Powershell requires Basic Authentication, and therefor must be enabled on the system you are connecting from.

Tip: Did you know you can view the release notes of the installed Exchange Online Management module by inspecting the ReleaseNotes property, e.g.

(Get-Module ExchangeOnlineManagement).ReleaseNotes