Hello,
I was trying to grant a shared mailbox folder permissions to another mailbox, so that someone logging into the shared mailbox directly can access a folder (such as calendar) located in another mailbox. I'm doing this in powershell.
However the following error message appears:
The user "mailboxname" is either not valid SMTP address, or there is no matching information.
However when granting folder permissions to a mail-enabled security group and adding the shared mailbox to this group, this works.
Is this by design or a bug?
Microsoft documentation on add-mailboxfolderpermission say that for the user parameter "Valid values are mail-enabled security principals (mail-enabled accounts or groups that have security identifiers or SIDs that can have permissions assigned to them)". I would think that shared mailboxes are mail-enabled accounts.
Microsoft 365 support are just as baffled as I am about this one and at first tried to say it's not supported, but then finally found this workaround using groups.