Email from Microsoft titled "Action Needed – You may lose access to some of your third-party mail and calendar apps" Is this a scam?

I called Microsoft for help and they put me onto a chat with someone who said it was a phishing email and I had to change my log in details and create an alias name as a primary email. I was told not to respond to this email, which now I find out is genuine. I was on the phone for 45min all to no avail at the end. I am just hoping after the 16th I can still receive emails. By the way I am 73 and have children who are of no help to me at all in this matter. I even asked a computer geek to help and he didn't know what to do either!

The apple mail on my iphone is fine.

But the apple mail on my macbook pro is not. When I tried to remove the accounts and re-add them, there is no option for "outlook.com" in the menu. So, how do I fix it?

I don't have kids either but I don't live in a jungle where my neighbors are only animals. There are other people (a.k.a friends). I'm just presenting the options to you end users but if you insist on having one and only solution (Microsoft free help), I have no more suggestions. Good luck.

From the Support Article:

Modern Authentication Methods now needed to continue syncing Outlook Email in non-Microsoft email apps

If you use Outlook for Windows: 

Outlook supports Modern Authentication in all current Microsoft 365 subscription SKUs and Outlook 2021 LTSC (any SKU with build 11601.10000 or higher) when connecting directly as Outlook.com. If your Outlook is configured to connect to Outlook.com using POP or IMAP, Modern Authentication is not supported. This means that when Basic Authentication is fully deprecated, it will no longer connect.  For this scenario, you have a few options:

Option 1: Get a newer Outlook email app which supports Modern Authentication

If your Outlook client does not support Modern Authentication, you will need to upgrade to the latest version and then setup using Outlook.com Sync. You can either purchase a new Outlook License, use the Outlook that is included in your Microsoft 365 subscription, or download Outlook for Windows for free.  

Option 2: Switch to Outlook.com/Exchange Syncing

Instead of using POP/IMAP and SMTP, create a new Outlook Desktop profile and then add your Outlook.com account using automatic account configuration, which will add the account with Modern Authentication. To do this, please use the following guidance:

1. Create a new Outlook Desktop profile. For more information, please go to Create an Outlook profile.
2. Add your Outlook.com account. For more information, please go to Add an email account to Outlook.

The following versions of Outlook Desktop do not support Modern Authentication for Outlook.com:  Outlook 2007, Outlook 2010, Outlook 2013, Outlook 2016 MSI, Outlook 2019 LTSC. Any release of Outlook Desktop with a version less than 11601.10000 does not support Modern Authentication for Outlook.com.

It is not a scam, it's a blanket email sent to everyone with an Outlook.com email account. I got one also. In my case, it will likely mean that my old Lumia 928 Windows Phone that I've kept alive with an App Specific Password will quit since App Passwords will not be supported after the change.