Why is this happening?
Are you being swamped by emails and messages that are from "companies"? It's spam. spam is not real information from real companies, it is something someone made up to annoy people. But whatever you do, do not open attachments. It could be a virus.
How can I stop it?
If you are getting to annoyed with spam, like everyone else in the world, there are ways to prevent it from happening. First, get spam filters. Will make it so yo do not see the spam emails. Second, DO NOT REPLY. If you reply then more spam senders get you email address and more spam can get sent. Third, have a one-use email address. This means that you sign up for a server and then your email disappear but you are still signed up, but there is no way spam can find you.