Getting "MICROSOFT SUGGESTIONS" in my Outlook Calendar that appear to be spam

This just started for me in the last two weeks and is horribly annoying. 

They are associated with emails that are extremely obvious spam and the domains (stuff like “ADT <******@kill-fat-quick.spam.com> for example) are giveaways. Microsoft either needs to filter spam better or to give an option to toggle off “Microsoft Suggestions”. This issue doesn’t effect Gmail or iCloud and shouldn’t have ever been added as a “feature” we can’t turn off.

I'm getting the same thing, and although Robert is saying he doesn't see an email showing up as the cause, I do - but it's in my junk email. How is junk email able to trigger a calendar suggestion?

Thank you Brian, the problem is that I have never received an email for these events. That was my first thought and I looked for them to block.

I have actually found 2 possible sources of these in my Junk Folder. I actually went into my Junk Settings>Junk Email Options>Options Tab and my email Protection is (and always has been) set to high. Then I went to the International Tab and block ALL the options on both "Blocked Top-Level Domain List" and "Blocked Encodings List" as I get a lot of international Junk Mail. I don't need to receive any International emails so turning them off will not affect me.

I don't know if the sources I found are the ones that created the Calendar Event but I hope it stops it.

Now the problem is how do I get rid of the events?  I was able to get rid of them off my Desktop Outlook by "Declining" but I am not able to remove them from my iPhone. Any suggestions? And how does this happen if the email gets sent to the Junk Folder?

Thanks,
Bob

for me I deleted them by logging into outlook.com and deleting the event there.

I’d be afraid to ever respond with “decline” (or any of the options) because that usually notifies the sender what your response is, and now the spam source has confirmed your email is active.

Anything delivered to your Junk Email folder is already considered blocked and blocking it again will not have any extra effect. If events are coming in on messages that the server recognizes as junk, that is a Microsoft problem. I know how to contact some Outlook MVPs and will ask them to bring this to the product group's attention if they can.