I have recently had issues with my Exchange 2003 server, OWA mis-configured and being placed on blacklists at the beginning of the week. I now have OWA working correctly and have been removed from all the blacklists however when I send an email to one of my customers they never get the email. the next day i get a delay report then the following day i get an NDR email. I have sent emails to that customer and have looked in the message tracking of Exchange and it says "Message Transferred to through SMTP" which I assume means it was sent out however I don't see any of the receiving servers like I would if I sent to a Yahoo email. How can I find what is happening to these emails. I can send to the customer from my Yahoo account and they get it but not from our Exchange account.