-MaxSafeSenders limit on Office365
Allow admin to change the number of safe senders to match max contacts thus allowing admin to set junk mail to avoid contact list. understanding this is a potential performance issue maybe it can be done by user instead of globally.
Michael Donovan commented
I need to be able to increase the maxsafesenders value for a particular mailbox (used by PC GO.) This mailbox is getting added to our restricted user on a regular basis.