Two managers in one of our departments wants to have Full Access Permission to about 10-15 users mailboxes who work under them. Traditionally on a single user access basis I would just give the manager full access permission and add the Mailbox to their Outlook client under "Open these additional mailboxes" so that the other mailbox was displayed in their folder list. I worry that adding an additional 10-15 mailboxes this way long term will slow down the managers Outlook Clients.
Are their any other known good solutions to a situation like this? Obviously I could teach the managers to just click "File > Open > Other User's Folder" and type in the persons name but that could become tedious if someone is out of vacation for a week and they have to frequently check their inbox.