Lost Email

Hi, I’m hoping someone can help me..
I’ve stopped receiving around half of my subscribed newsletters. I’ve contacted my ISP and they have no idea (Not a spam filter anyway)

I use Microsoft Outlook, and realised I had somehow set the Security Zone to restricted. Is it possible it was somehow rejecting the email without my knowledge?

If I have been blacklisted?? by the newsletters for too many rejections, is there an easy way to fix the problem without contacting every one?

Thanks for your help