Using classic Outlook for Windows in business environments
Hello Sameer,
Thank you for reaching out to the Microsoft Community. I'm happy to help.
It looks like you are receiving these code requests because someone who has your Outlook email address is attempting to gain access to your account. This does not necessarily mean, however, that they already have access to your account. On the contrary, without these codes, they won't be able to access your account at all.
In order to stop these messages, I can only recommend that you log in to your Microsoft account and modify your security settings so that you don't receive them in your Gmail account. For information on how to change your associated email address for your Microsoft account, kindly visit the page below.
https://support.microsoft.com/office/761a662d-8032-88f4-03f3-c9ba8ba0e00b
I do hope I was able to help you with your issue. Please do not hesitate to reach out again for any other concerns.
Regards, Arjay O.