How to verify if an email address is legit

Dear Katie Lasswell,

Thank you for posting in the Microsoft community. 

Regarding whether an email address is legitimate or not, it needs to be judged according to the specific behavior of the address.

May I ask if you have received emails from this address?

The official sender address of Microsoft regarding account information is @accountprotection.microsoft.com. If the address fi***c@outlook.com sends you an email prompting you about changes to your account information or the like, then this is a typical phishing email address. Please directly mark it as a phishing email.

Can I trust email from the Microsoft account team? - Microsoft Support

If this address sends you other types of emails, please don't click on the links in the body of the email. Instead, go to the corresponding platform to verify whether the information is true or not.

If you can't tell, you can share screenshots of the specific email content with me and let me help you analyze it.
(If the screenshots are not uploaded correctly, please refresh / change the browser and upload them again.)

Thank you for sharing more detailed information with me. I'll keep an eye on this thread and give a further reply as soon as possible after receiving your reply. I'm looking forward to your reply and wish you all the best.

Best Regards,

Ulrica.W - MSFT | Microsoft Community Support Specialist

I know the address is true, so how do I verify it with microsoft so it is accepted?