Appointments received for wrong user

[MustangPriMe]

I regularly receive appointments that have been sent to another user.

The user in question still receives the appointments as expected. It only seems to affect me, and I only receive appointments sent to that one user.

Outlook shows me that the appointment was "Received for [User name]".

I can't see anything in the Active Directory user properties that refer to me.

Any ideas what's causing this, or even better, how to stop it?

Thanks
Paul