I have setup Exchange2003 and now my users can receive internet emails, but they cant send mails back to any user in the internet. Let me recreate it to you. If you send an email from your yahoo account to a user like [email protected], the user at everyone.org will receive it, but when that user replys back to the email, the email never gets back to whoever sends the email. Before this Exchange migration, they were using a web based system hosted by an ISP company. but the funny thing is if you logs into the based system and sends an email, the email gets out and reach its destination. All the MX records are setup correctly. Please help out.