How to migrate Shared Mailboxes with On Demand Migration (ODM).
解决办法
Create and run a Discover task from the Accounts tab.
Once discovered, perform one of the following:
if the Shared Mailbox exists in the target already, create and run a Match task.
if ODM is creating the target Shared Mailbox, create and run a Migrate Accounts task
Create and run a Mail migration task. You will be prompt to choose a license option however if the Shared Mailbox does not have a license on the source and target, then an Office 365 license will not be applied.
Note: ODM does not consume an ODM license for Shared Mailboxes