Users in a hybrid deployment can’t access a shared mailbox that was created in Exchange Online [Resolved]

Users in a hybrid deployment can’t access a shared mailbox that was created in Exchange Online [Resolved]

  • Date: 24/04/2018 10 minutes to read

    Applies to: Exchange Online, Exchange Server 2016, Enterprise Edition, Exchange Server 2016, Standard Edition, Exchange Server 2013 Enterprise Exchange


These issues can occur when the shared mailbox is created by using the Exchange Online management tools. In this situation, the on-premises Exchange environment has no object to reference for the shared mailbox. Therefore, all queries for that SMTP address fail.
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Use Windows PowerShell to control how external sharing invitations can be accepted

You can use Windows PowerShell to turn external sharing on or off. Using the SharePoint Online Management Shell, administrators can now enforce new controls over how external users accept invitations. When enabled, the RequireAcceptingAccountMatchInvitedAccount parameter requires external users to accept invitations with the email account with which they originally received the invitation.

  • If this parameter is not set or is set to null:

When a user shares with an external user, they enter an e-mail like, and an email is sent to Stephen at When he attempts to accept the invitation (by clicking the link in the email), he can log in with any account he wants to use. For example, he could use,, or even The sharing email can be forwarded and accepted by anyone. This system ensures that external users who use email aliases or who do not have a Microsoft account or organization account are able to accept the invitation.

  • If this parameter is set to true:

The RequireAcceptingAccountMatchInvitedAccount parameter ensures that the user who receives the invitation is also the user who accepts it. If an invitation is sent to, only a user who can log into is able to accept the invitation. Any other email account displays an error page that directs to user to use the appropriate account.

Using the SharePoint Online Management Shell, IT administrators can now require that all external sharing invitations be accepted only by the e-mail address that was originally shared with.

To enable this feature, simply run the Set-SPOTenant cmdlet and set the “RequireAcceptingAccountMatchInvitedAccount” parameter to true.

The parameter accepts two values: True or False.

True-User must accept this invitation with

False– When a document is shared with an external user,, it can be accepted by any user with access to the invitation link in the original e-mail.

Administrators who desire increased control over external collaborators should consider enabling this feature.

You have first to download the online management shell

Then connect use the following command


Then add the URL of the office 365 administration website

Which will be



Then you will be asked for the SharePoint credential to connect


Then run the following command

Set-SPOTenant -RequireAcceptingAccountMatchInvitedAccount $true

Set-SPOTenant -RequireAcceptingAccountMatchInvitedAccount $Null