My Outlook inbox is suddenly getting a ton of spam and I don't know how to stop it

1000 in a day?! Move away.

I am moving to iCloud, it has the advantage that you can create up to 3 alias, so I never never never put my real mail into any registration. Can use 2 and use the 3rd for transfers. If sometime one of the aliases get too many spam, just create a new one on the 3rd alias, change your registration mail from the sites you want to preserve to the new created alias, and delete the old spammed alias.

Meanwhile, try to set your mail config more strict. Open your outlook mail in a web browser, click on the config icon (the gear at top right), then in the Unwanted Mail option, go to all down and check the 2 filters. Add then items in the safe lists you want not to be blocked (like wanted mail listing and etc), I suppose you don’t have to add your contacts they should pass the filters.

My problem appears to be 10x worse than what I've read here. I am getting 1000, yes 1K, of junk emails 2 or 3 times a week. Frankly, I don't have time to send them to the junk file one by one. It's driving me crazy. I have a Microsoft Outlook email account!!! All they can say is how to block a single item, one at a time.

I know how to block emails. The problem is the overwhelming number of them. Over 1100 today!

Just today I got entries in my Calendar!! You must be kidding me. Invitations pointing to Google docs to accept or decline.

Revised and all my outlook calendars are private, none public or published, so it is supposed for all them to be PRIVATE!

This is hilarious. Well then removing Outlook Calendars from sync too.

GMail does NOT have a lock on a better system!
I get plenty of SPAM through gmail. Plus it also filter non-spam into the junk folders.
And some of the SPAM I get with other servers come from spammers using gmail addresses.
I have few issues with my Comcast account, but I only use it for a very specific purpose ... but even there it has started to receive junk mail.
There is a larger systemic issue going on that NONE of the email servers or email client providers have been able to resolve.
And it will not belong before this is the case with text messages. As one goes, so goes the next.