Using older versions of Outlook for Mac in business environments
Dear Stephen Taylor2
Welcome to Microsoft Community.
I understand that you are having trouble on check if the email is a scam.
First of all, I want to explain to you that this email is indeed sent by Microsoft. Usually, Microsoft will send this email to users who is still using the old version of authentication.
You can refer to the following website:
To find out which version of Mac Outlook you are using, you can refer to:
The new Outlook for Mac - Microsoft Support
What version of Outlook do I have? - Microsoft Support
For your configured Microsoft mailboxes such as Outlook/Hotmail, you may need to remove them from your Outlook or Mail application and add them again, making sure they are selected as the Exchange/Outlook.com protocol when adding them.
Once the addition is confirmed, you do not need to do anything after September 16.
I hope my explanations and instructions can help you.
Thank you for your time and understanding.
Sincerely,
Hardyjoe.J|Microsoft Community Support Specialist