The delegate can then move or copy the items from his or her own Sent Items folder to the manager's Sent Items folder.
We have an Exchange 2010 server and multiple users with Outlook 2011.
As an alternative, the manager can grant permissions to his or her Sent Items folder to the delegate.
To grant access to your private items, do the following: Important: You shouldn’t rely on the Private feature to prevent other people from accessing the details of your appointments, contacts, or tasks.
To ensure that other people can’t read the items that you marked as private, don’t grant them Reviewer (can read items) permission to your Calendar, Contacts, or Tasks folder.
You can grant a delegate permission to read items in your folders or to read, create, change, and delete items.
By default, when you add a delegate, the delegate has full access to your Calendar and Tasks folders.I've setup the office 365 account in outlook 2016 using autodiscover which all works ok.