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Lefty's avatar
Lefty
Copper Contributor
Mar 04, 2025

Any Work arounds for not being able to share mailboxes across Multi-Tenant Organizations?

Hi,

Multi-Tenant Organizations make a lot of things fairly seamless, but you can't have a shared mailbox that is shared to users in two tenants within the organization.

Which is a bit of a problem because I have a situation where that would be the ideal solution.

So does anybody have suggestions for the next best thing?

  • There is no way to access mailboxes cross-tenants, MTO changes nothing in this regard. If you need such access, provision the users as "members" and grant them Exchange license in the "resource" tenant.

    • Lefty's avatar
      Lefty
      Copper Contributor

      Hi,

      Thanks for your response

      I'm aware that you can't access mailboxes cross-tenant even with an MTO, which is why I specifically asked for suggestions of "next best thing". To word it another way, in a situation where a shared mailbox WOULD have been the ideal solution (if it was possible), what approaches have people used instead to tackle the situation in an MTO, preferably ones with the least kludging necessary.

      With regards to your specific suggestion, MTO synched users are already members in the destination tenant, can I assign an exchange license to that account to allow shared mailbox access or do they require a separate account on that tenant?


      • It's best to create a separate user account, if you are going to assign a license on it anyway. Exchange is not really designed to work with B2B/MTO.

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