Hi,
we have deleted distribution group, and then created shared mailbox with same name and users in it. When someone is sending from outside mail to this shared mailbox, it's working correctly. The problem is if someone from inside tries to send to this new mailbox,
it gets the following error:
Remote Server returned '550 5.1.1 RESOLVER.ADR.ExRecipNotFound; not found'
i tried to delete autocomplete of single mailbox, delete the entire autocomplete list. But no success.