New 2003 Exchange Server not sending email to the outside

I have setup an exchange server for a company.  Internal mail works correctly and mail can be received from the outside world.  I am using Cablevision for business  and port 25 is open both ways.  I have my mx record setup and pointing to my external ip address.  Why can I not send mail to the outside?  My internal domain is setup as and my mail server points to the internal dns server (DC).  Could that be the prob?  DO I have to change something in my internal DNS?  I really need to get this working ASAP so any help is much appreciated.

Who is Participating?
Is your internal DNS server also set up with forwarders?  If not, the Exchange server won't be able to resolve mx records for other domains.

To confirm that port 25 is open outbound, from the exchange server open a command prompt and try to telnet to an external mail host on port 25.  "telnet hostnamefqdn 25"

If not, you may need to set up a smarthost and point to a cablevision server in the SMTP Default Virtual Server.
Can you connect to any remote mail servers? Having your DNS pointing to internal DNS servers is the normal way of doing things, so shouldn't be a problem.

jdltekAuthor Commented:
I restarted the server and mail started sending.
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.