I couldn't determine an appropriate forum for email issues, so I'll start here.

For many many months, well years really, I've been getting email replies to emails I've never sent.

Either non-delivery reports, or automated responses. But every now and then, from an actual person.

The addresses I've supposedly sent emails to are old, I haven't used most of them in quite some time, but there a handful that are still relevant.

Some are to old workplaces, which have never been on my personal computer, that I can recall anyway.

Many scans over time with various programs have found nothing untoward, so I don't think my computer is the "sender".

Talking to the real life people who have received these emails, they are definitely typical of scam/spam, containing an enticing message and something to click on. 

The email address that is being used as the sender is not one I have used for sending email for ages, but it still current is as much as my Microsoft domain is registered to it.

I can only presume that something "out there" is doing this.

But is there anything I can do to stop it.