I am running windows 10 and using an old Live.com mail account. Same as Hotmail and now Outlook.com. This problem only happens in eM client. Every time I open my mail I get the same error message. I hit ignore all and hide and it goes away for a while. All along my send and receive is working just fine. I have noticed that when I send myself an email it is sent to the junk folder instead of my inbox. I have added my email to contacts a couple times now to see if that would help but no luck there. Attached is the error and the logs. I have opened the account setting and reentered them but it keeps popping up. Can someone help me?? please. 
If you require assistance from support, then please open a support ticket directly with eM Client. You will need a Pro License to do that.
Outlook.com is a headache with spam, and I am not surprised that sending yourself an email it ends up in the Junk Folder. You will need to change those settings using their web interface, or contact their support for further assistance.
For the error issue you can disable the error popup if it is otherwise working OK. You will find that in Menu > Tools > Settings > General > Operations Window.
But I suggest rather fixing the problem. One option is to remove the account from eM Client, and then add it again. See if that helps.