Help with IP change

Hi people. I am new to the forum and beginner in setting up a network. I recently encountered a problem with my microsoft exchange server which handles our small business email.

I have a Small business server by microsoft 2008. Recently, our router broke down and I had to change routers. I have a static IP and when I updated the IP address in my computer, my email service is not working properly.

I updated the DNS in my domain hoster godaddy but my email is still not working properly. I can send email when I am logged in the server, but cannot send email from the other computers in my server and totally can't receive any emails.

Also, remote access from any computer is down. Hope somebody can help me out. Thanks