I have run a server with a similar setup for many years. And some people get really confused. It can be quite funny sometimes.

The best moment was my SO explaining to someone on the phone, why the email address included their company name.

Paraphrasing: If you get hacked or sell my email I will know it was you. So don't sell it, and make sure you stay on top of your security.

I used to contact companies by email after they leaked my throwaway email address, but I don't any more, because some got angry and others were just confused.