I set up Safe Senders with Office 365 by uploading a list through Outlook 2010. A few days later, I uploaded an expanded list. But then within 10-20 minutes, the list reverted to my old list? What the heck?
Finally a Tier 3 support guy asked, “Do you have a smart phone on that account? We’ve seen this since Android phones became popular.” Well yes I have a smart phone, but it’s a Windows Phone 7, which I chose mostly because of Exchange issues in Android.
Apparently the junk list on the smart phone (which I can’t see or modify) overwrites the list on the server. The tech’s suggestion was to remove the Exchange account from the phone, update the Office 365 safe senders from Outlook, then re-add the account to the phone. Sure enough, this time the new list “stuck.”
The tech said after the list should stay in sync going forward, but when I tried another bulk update, it again got clobbered. Fortunately, just turning off the phone for a few hours, without deleting the Exchange account from the phone, was enough to let me upload a new Safe Senders list.