Thank you for reaching out to us. We are sorry that you haven’t been able to block certain contacts. We are considering bringing this ability to outlook on the mobile browser. However in the meantime you can do this from outlook.com on a desktop or a laptop. Follow the steps mentioned here https://answers.microsoft.com/en-us/outlook_com/forum/all/how-do-i-block-the-email-of-someone-harassing-me/d2d4a775-b8c8-4c38-bcc6-404a940030e8.
An error occurred while saving the commentWilliam Acciu commented
I'd like a block function for the sake of ownership of my email site
We are sorry about the spam mail you’ve been receiving. We are looking into improving the filtering.