Fake e-mails on my domain are registered on sites!?

Question

Email

Good afternoon, dear members of the Toaster community.
Recently, messages from Instagram began to fall on my mail, they say, welcome to Instagram. Moreover, e-mail addresses from my domain.
For example, [email protected]
I have mail for Yandex domains connected and letters to non-existent mailboxes are redirected to my main e-mail.
The question is: why is this incomprehensible someone trying to register somewhere with fake mail on my domain and does this threaten me with anything? Is there any way to prevent such dishonorable actions?
Thanks in advance for your answers and have a great mood!

Answer 1

it doesn’t threaten
why - different tasks, usually multigeneration of users, turns someone on,
but in the face of your domain, he found an excellent assistant, from whom “there is no such user”

Answer 2

Doesn't threaten anything.
I have such letters falling to a separate user, I never read them, I just kill his mailbox from time to time and that's it. Let them at least swell up to register :)
Why did I do this?
Because otherwise there is a correspondence between Postmasters that the user Petya, who is not there, writes a letter to the user Vasya, who is not there. This correspondence can last for a long time and it will be completely meaningless :)