I received an email into my Hotmail junk folder overnight. It's typical scam content about my entire digital life and personal details being obtained, and them trying to extort money or they will release these files to the darknet. Blah, blah, blah.
What intrigues me is how the email address of the sender is, character for character, my Hotmail address. The same account/address I received the email in.
How do they achieve that (please make the explanation concise and not too jargon heavy)?
More importantly, should I be concerned that they used my email address as the sender email address (i.e., have I been hacked?)