Outlook 365 showing reminders for other people's calendars

Question

(META: This is not related to Outlook Reminders showing other people's reminders - that question is for Outlook 2016 and all of its answers are similarly oudated).

After my work migrated our mailboxes from G Suite to Office 365, I have begun receiving reminders for appointments in my colleagues' calendars. This appears to be due to a misconfiguration where calendars that had been marked as "Shared" in G Suite were added to the "My Calendars" list in MS365, meaning users received reminders for the appointments there.

I removed the calendars from Outlook and from the web app and they are not shown in either interface anymore. Despite this, I am still receiving reminders for these people's calendars (four or five people), which is naturally distracting. The reminders do not occur in the web app, only in the Outlook Windows app. This comes after deleting and recreating my Outlook profile six or seven times, uninstalling and reinstalling Outlook, and using the /cleanreminders flag. Nothing changed anything.

When opening Outlook, in the bottom-right after saying "Syncing Inbox" it switches to the calendars, at which point it says Syncing [email protected]_4fd904d983ef84a3de, where the email address is one of one of these shared-calendar colleagues and the hash at the end is a random hexadecimal collection of characters. When double-clicking one of the reminders' contents it brings up the appointment proper, which the status bar reads as being "In folder [email protected]", even though such a folder does not and should not exist. I feel as if were I able to find where this folder it's pulling from were shown to me I could delete it with prejudice, but this appears to be the only part of the product that acknowledges its existence.

Is there anything else I can try on my end to delete my profile's association with these other calendars or is this something my work's tech support need to do? I have of course enlisted their help but we haven't managed to get to the bottom of it yet.

Answer 1

Unfortunately, the answer was an administrative oversight. I had to file a ticket with upper-level Support who did something to fix it. Whilst this is not an "answer" in its own right, it is an answer inasmuch as it is the only action the reader will be likely able to take. The problem is beyond user control.

Answer 2

I removed the calendars from Outlook and from the web app and they are not shown in either interface anymore.

I notice that you have removed the calendars, how did you remove them?

at which point it says Syncing [email protected]_4fd904d983ef84a3de, where the email address is one of one of these shared-calendar colleagues and the hash at the end is a random hexadecimal collection of characters.

Looks like the problem is related to the shared calendars. How do other users share their calendars with you? It's suggested that you could confirm that they have stopped sharing the calendar with you.

If you confirmed the above two points, please delete and recreate the Outlook profile again and check if the issue still exists.

If the reminders still pop up, please try the following steps as Allen Wang mentioned in this article to check if there're any differences: Outlook appointment reminders coming from deleted calendar