Hi @Robin G. Stout
There is no way to disable mentions. If you want to use the mention feature when sending emails, you can uncheck the Suggest names to mention when I use the @ symbol in a message(requires restarting Outlook) option. But this one is only for sending emails, it won't stop others from tagging you with that @mention.
By the way, Outlook has an official feedback portal where customers can send feature requests or suggestions to the product team. To get this feature more quickly, I have found a similar post in feedback collection website, and you could vote for it. Many features of our current products are designed and upgraded based on customers’ feedback. You can also make suggestions on that website and hope Microsoft will notice this in the future. Thank you for your understanding and support!
Hope this helps!
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