As of 8/24 I stopped receiving emails in my outlook.com account from my main email which I am currently forwarding to outlook. My main email is also setup as an alias account on my outlook.com account so that my sent emails show as they are from my main account.

I have checked all the filters and blocks in outlook.com and there is nothing there. I even tried adding my main email on the "Safe List" but of course I got an error since the instructions clearly say any emails that is not that one. 

My main email is part of my website hosting and uses our domain name (ie. <main email>@<domainname>.com). Our 3rd party hosting partner did some checking and they said that "outlook has marked mail from our server as spam".

Can you please help?