sent to junk

I have 2 addresses for mail, one of course is primary and out of the blue, messages to both were going to junk for, so far, 2 senders. Now I have adjusted things in the junk folder for Talktalk account and that is seemingly now resolved, but still not so for the primary one - the Outlook.com . One of the senders is a friend and I had her send  a test message. What can the solution be, is it with Client or the Outlook web mail suite please?

With Outlook.com, you need to add the sender’s address to the Safe Senders list using the web interface for that account.

If that still does not help, check that the address or domain is not in the eM Client Blacklist. You will find that in Menu > Tools > Rules > Blacklist. To test if it is eM Client that is moving the messages, untick both the Blacklist and Spam filter Rules and see what happens.