Email Issue – Outgoing Email Problem

I just implemented Exchange 2003 Server. I’m having an issue where single quotes are placed on email addresses of outgoing internet email addresses. This did not occur prior to implementation.

I’m getting some bounceback messages stating the email addresses and domains do not exist because I assume it is reading those quotes around the email address. I need a solution to this issue. I use Outlook 2000 right now – but will upgrade to Outlook 2003 shortly.
Thanks for your help.