Delegate access to shared mailbox to a user in another domain

[xeno85]

Hey there,

I am just seeking out expertise on delegation to shared mailboxes with external users.

I have found this article https://learn.microsoft.com/en-us/answers/questions/466102/delegating-a-mailbox-to-another-domain-fo... on delegating to external users and at the time it does not seem possible to delegate mailboxes to external users.

This article was from 2021 though and seeking to see if much has changed in two years. I’m open to options/solutions in exchange online too. We are splitting with our current organisation but we already have our Azure/M365 tenant with Exchange Online.

The requirement we have though is that we need members from the old organisation to still send emails from shared mailboxes within our organisation when we split. In the ideal scenario we’d love them to still have access to the mailbox through the outlook client.

All options are welcomed.

[#2]

No such thing, delegate access is only available for internal users ("members").

[#3]

Thank you Vasil. Sounds like nothing has changed since 2021.

The only options I’m seeing are to create dedicated internal accounts for these users or use M365 group mailboxes in B2B using Exchange Online.

Would there be creative ways to add these shared mailboxes to their outlook client?

[#4 · Accepted solution]

Nope, nothing new in this space. Microsoft 365 Groups offer nothing either, even though they're often touted as replacement for shared mailboxes. If you need direct access to the shared mailbox, you will need to provision internal accounts. If you just need access to new messages, configure some form of forwarding to the external address(es).

[#5]

Thank you Vasil, this has at least solidified my approach.
Genuinely appreciate you sharing your expertise in this space.
We need send as delegation sadly and emails coming from a specific domain as they’re going to outward facing customers.