Hi Renee2021DD
I am Igor, a Microsoft Independent Advisor and I will be glad to assist you.
I am sorry for your frustration with this account email issue.
But the good news is Yes, you can use a non-microsoft email set to your Microsoft Account, you can add a non-microsoft email to your current microsoft account
Just follow the steps below:
1. Sign in to Manage how you sign in to Microsoft with your Microsoft account.
https://go.microsoft.com/fwlink/?LinkId=529489
2. Under the Account aliases section, select either Add email or Add phone number.
If you selected Add a phone number, go to step 5. If you selected Add email, choose whether to add:
A new email address. Select Create a new email address and add it as an alias, and then follow the instructions.
A non-Microsoft email address (such as an @gmail.com or @yahoo.com email address). Select Add an existing email address as a Microsoft account alias, and then select Add alias.
After you've added the email address, you'll be asked to verify that you're the account owner:
Select Verify next to the new alias. A message is sent to the account for verification.
After you receive the message, select the included link to confirm that you own the account.
If you selected Add a phone number, follow these steps:
Select your country from the list.
Enter the phone number you want to use, and then select Next.
When you add a new phone number, we'll send a text message to that number to verify it. Enter the code from the text message, and then select Next.
Once you have added an alias, you can select it to be the address you send email from when using Outlook or Outlook.com.
https://support.microsoft.com/en-us/account-bil...
Now you can log in on your Teams app or Web using your yahoo mail.
Hope it helps and let me know if you need anything else.
Best Regards and Stay safe.
