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

When I click on notification to see what they are, they disappear from the notification section on my phone not even opening my calendar or email box so I can't check which junk emails sending me a notification. A few days ago I found some strange titles on my calendar and I deleted all thinking I must have pressed something to activate a service on my calendar. I tried to deactivate whatever that was but could not find how.

I use a surface pro and an android phone. 

I keep getting notifications on Microsoft Suggestions almost every half an hour.

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

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 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.

Thank you for this advice. 

I couldn't find it after initial pop up. But have just found email in junk.