Hello everybody. In the company I work we got a problem with our email system, we can receive emails from hotmail, yahoo, gmail or any external site but we can send to anywhere and receive internal mail.  We have an exchange server, an isa server, and we manage our dns servers. the problem began when our ISP change our public IP we did the changes but now he have been in problems with the mails for more than two months. Any ideas?????

Thanks

Hi,

I faced a similar problem few days earlier. 

You might try the following:

As you did the changes, please make sure if you have the old DNS still alive somewhere....