Sending, receiving, and organizing email in Outlook.com
If the Spam is being delivered to your Junk folder (not your Inbox) - There is no way to stop it or automatically delete it. This is a long standing complaint from numerous users, myself included.
All I can suggest is that you look at the Answer by "Hornblower409 Apr 23, 2026" in
https://learn.microsoft.com/en-us/answers/questions/5867493/how-to-solve-receiving-a-huge-number-of-spam-email
That Answer has instructions for how to vote for some Feature Request that would give users more control over their Junk folder and some suggestions for MANUAL processes you can use to pick out and Delete any "known" Spam from the Junk folder so you don't have so much to sift thru looking for legitimate emails.
I am seeing reports on Reddit of a similar nature. Multiple new Spam in Junk every second, non-stop. Might be a Subscription Bombing, or your email was recently disclosed and the Spammers are piling on.
Is there any common element to the Spam? e.g. Most with variations on a single Subject? Most from a single source?