I would like to knowif there is a way in exchange server 2003 to find duplicate email addresses. Two users in active directory are using the same email addresses and we have located the one and cannot find the other. When I try to add a new email address in the email address tab from right clicking on properties on the user, it says cannot add email due to duplicate email found. One of the users cannot receive there emails because exchange is converting them over to a default email address domainthat is not valid. Is there anyway to check for duplicate email addresses in exchange using a certain module?

I wrote an article on that exact topic at the link below. There are plenty of ways of doing it - just choose the one you like. http://www.msexchange.org/articles/Finding-Duplicate-SMTP-Addresses.html

Thanks Neil for the help!!!. The article was very informative and helped me resolve the problem