Imagine two users A and B.User B has editor rights on mailbox A via delegation.

Delegation settings:

User A should not receive any invitation (calendar appointments). All should be routed to user B. It works fine when you are connected to mailbox via Outlook. Problem is that sometimes it does not work when user is connected via his iPhone (he receives calendar appointments in inbox). I know that this feature for MS products and therefore it works on MS Outlook. But user A told me that it worked in the past also on iPhone with user C. Problem is that nowadays it does not work perfectly for user B. Do you have any suggestion please? Thank you in advance.