my outlook email is not delivered

Hi. I'm Brian and I'll try to help.

It is 100% impossible for two people to have the same address. You may have @outlook.com but they may have @outlook.uk or @outlook.co.uk or they may have an address with kumars in front of the @ and you have kumarsh, but no two addresses can be exactly alike. I had something similar happen to me. I have an address that contains the word "bear." Someone else had the exact same string, but it contained "beer" instead of "bear." They purchased some concert tickets and used my address so I received their communication from the ticket company. Somehow (I no longer remember how), I was able to determine the misspelling and contact the ticket company so they received their communication.

How do you access your mailbox? This forum is dedicated to Microsoft 365. Are you using classic Outlook, new Outlook or Outlook online with a web browser? If you use a mail client, log into the mailbox with a web browser to see if the messages are there but not reaching your client. Check the activity log at https://account.live.com/activity to make sure there are no successful but unrecognized logins. Check in https://outlook.live.com/mail/0/options/mail/rulesto make sure there are no unrecognized rules. Check in https://outlook.live.com/mail/0/options/mail/forwarding to make sure there is no unrecognized forwarding. Try to end a message to your Yahoo address and see if it moves to the Sent Items folder. Make sure you receive it. Check your storage usage at https://outlook.live.com/mail/0/options/accounts-category/storage to make sure both your Email storage and your Microsoft storage are under their quotas.

If none of this helps, please write back.