Configuring preferences and options in Outlook.com
My inbox inundation also started around 17Jan2020, and I also have the box checked to only receive emails from safe senders list. Clearly selection this is being ignored as I was getting spam emails once every 90 seconds. This is a new event for me as well. Up until a few days ago the junk filter was catching everything.
Funny thing is that it seems like most of the spam is coming from ******@vertical-aff.com so I created a rule to block "subject and content" as well as "sender" as "vertical-aff.com". I also changed my PW. Now only a couple of inappropriate emails are sneaking through. I would be interested in knowing how to stop the vertical-aff source.