Hello, thank you for reaching out to Microsoft Q&A.
What is the exact error message the sender receives when they try to email to your address?
Send a test email from another one of your accounts to the affected email address. Check whether you receive any bounce-back error messages in the Outbox folder. If you receive an error, please share the complete error message here.
If the email is sent successfully, then please check your email forwarding rules and blocked senders list, and verify whether the messages have been routed to another folder, such as Junk or Spam.
To do that, open an incognito tab on any web browser and sign in with your Microsoft account here:
Email forwarding rules: https://outlook.live.com/mail/0/options/mail/forwarding
(Click Do not forward if your emails are being forwarded to another address)
Additionally, to prevent this issue from happening in the near future, ensure you protect your account with a strong password and enable two-factor authentication for added security.
How to use two-step verification with your Microsoft account