cc'd or bcc'd mail

Actually, does it really matter how your user is getting a copy of the email?

Just reply to the sender and state you re getting a copy of thier email and to correct their addressing.

If cc was used, your user's address would be in the cc list. If bcc, no way to know.

Your user could also be getting mail forwarded from another account -- for example if a unix user created a .forward file to forward his mail and put your user'saddress in by mistake. (typo perhaps?) This scenario is likely if the user is getting lots of mail from lots of people. If you can determine the original domain from the headers (view/options while reading the message), send a message to the user 'postmaster' at that domain, letting them know what is happening.

Good luck.

Following on from the above (and I agree the best thing to do is just contact the sender), sometimes when sending emails people simply type in a name (as oposed to a full address) and hit send. The idea being the message will be sent by matching names in an address book. You user may share a first name or something and is getting mail by mistake.
Also note the difference between a display name (what you see on the screen) and an email address can be entirely different. Right click on each of the recipients to see the full email address. By the way, if there are no other recipients, the user is probably being BCC'd.

Hi 1

You are using Outlook 2000. If you are getting mail in which your name is not there in the To, then it may be in the CC. Just check it.
If you can see your name then its OK otherwise just click Reply All and then see whether your name is there in the CC or may be in To. If it is not there then you are getting the mails in which Sender is putting your mail in BCC and there is no way to get rid of it.

It may happen that it will not show your name but in the address it may be your address.
For example, if you see the names then it may show the name as,

American Boy but the address may be yours that is Name may not be yours but address will be yours.
So check for each and every addresses after clicking Reply All or Just Double-click and select the name Double Clicking and then it will show you the address to which it is being sent.

Hope it works

Guru