Thanks Greg and Al for your help! Here is more info, 1. I have invert the scenario, in the place that I had the Linux Mail server now I have a Small Business Server running Exchange 2003. 2. Where I had the exchange server I have now a Linux email server. Note: that the email server are not the same mail servers that were running before. Some how I am still have the same problem??? From Place 1 I cannot send email to place 2. Place 2 I can send mail to place 1. Note:`I can telnet from other computers on port 25, but not from the exchange server.. thanks again.