On old hotmail.co.uk account keep getting messages from postmaster saying undeliverable

Question

really strange scenario. So my inbox on other old hotmail.co.uk account is being filled with messages from postmaster@outlook saying my message is undeliverable (but this seems to relate to message I am actually receiving from others) to a random email address ******@gmail.com. I've never heard of this email/person and have no idea how to stop this.

Answer 1

Hello,

Did this start recently or after any changes to your mailbox?

Check your recent sign-ins at https://account.live.com/activity, then in Outlook on the web go to Settings, Mail, Rules and Forwarding and remove anything you do not recognize. After that, change your password and turn on two-step verification at https://account.microsoft.com/security.

If the issue continues after these steps, the messages are likely from spoofing outside your account, and securing your account is the correct action.