[Closed] Why do I receive junk emails from my own address?

My guess is that someone (a bot) has a login to your account and is using it to spam everyone in your contacts list (including yourself)?

Change the password and use 2 factor authentication.

Because someone has harvested someone's address book with your address in it, and is spoofing mails from your account to a number of other accounts in that address book. Which also includes yours.

Not trying to be a dick, but people often jump to the 'my account's been compromised' conclusion in cases like this, when it's often not the case. It could be anyone who's ever contacted you that has had theirs compromised. Sitting emails and looking through an address book is incredibly easy.
However, still good practice to change your password and turn on 2fa if possible, as said above.

Not sure if Outlook online can do it, but some Webmail providers such as Gmail have a section in the options where you can see the most recent logins. See if you can check the locations of these.

I get them every now and then. As above, it's someone else's email list (perhaps a business) and doesn't mean your account is compromised.

I expect the motive is that they are more effective as if the sender is already in your address book it may get through the spam filter, and if you see it, you are likely to pay more attention as you recognise the sender.

They're not most likely not emails from your account. Address spoofing.

You should be able to click on the sender and see the actual email address it's being sent from.

Spoofing email addresses is trivial and has been since the Internet looked like The Matrix. It's got to appear to come from somewhere, might as well set sender = recipient as anything.

It's always possible that there's something nasty on your machine causing it, but it's increasingly unlikely. You could run a Malwarebytes scan and change your password to be on the safe side and enabling 2FA is always a good idea (doubly so on a primary email account which can be used to reset all your other passwords everywhere else), but the chances of you actually not being on a spam list somewhere is remarkably slim. And if you've got a common-sounding address on a popular platform there doesn't even need to be a data breech, I could readily guess that john.smith@gmail.com might be valid and send an email on spec.

You can right-click / mark as spam, but Hotmail seems remarkably shit at learning from this. I'm not convinced it does anything beyond moving it to a spam folder, even. It wouldn't be difficult, for instance, for them to automatically blacklist "your PayPal account has been limited" emails that don't actually come from PayPal.

As stated above it's easy to spoof an email address.

It's a tactic used to convince the credulous, or less technically aware, the the message is important. The psychology of spam is quite an intersting area, one theory is that spam full of spelling mistakes is instantly binned by those who can spell, thus reeling in those more likely to fall for scams.

Hotmail won’t allow me to block my own address

That's your answer. The spammers put your address as the sender because they know you can't block it. If Hotmail allows you to look at the full email headers you can see where it was really sent from. If you don't know how to understand the headers that may need some research but it's useful to know.