Click on the gear icon in the upper right corner of the screen, then on Settings. There you will see Filter Rules. Click on that and follow the prompts. Also, see here-----------
Scroll about halfway down the page for blocking instructions.
@1Mistycat wrote: How do a block a person on email ?
Also see https://www.xfinity.com/support/articles/spam-filters-and-email-blocking-new-experience "Set Up Email Filters" about halfway down the page.