New 2003 Exchange Server not sending email to the outside

Posted on 2009-04-17
Last Modified: 2013-11-30
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.

Question by:jdltek
    LVL 15

    Accepted Solution

    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.
    LVL 65

    Assisted Solution

    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.


    Author Comment

    I restarted the server and mail started sending.

    Featured Post

    Find Ransomware Secrets With All-Source Analysis

    Ransomware has become a major concern for organizations; its prevalence has grown due to past successes achieved by threat actors. While each ransomware variant is different, we’ve seen some common tactics and trends used among the authors of the malware.

    Join & Write a Comment

    Granting full access permission allows users to access mailboxes present in their database. By giving full access permission one can open and read the content of any mailbox but cannot send emails from that mailbox.
    In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
    In this Micro Video tutorial you will learn the basics about Database Availability Groups and How to configure one using a live Exchange Server Environment. The video tutorial explains the basics of the Exchange server Database Availability grou…

    728 members asked questions and received personalized solutions in the past 7 days.

    Join the community of 500,000 technology professionals and ask your questions.

    Join & Ask a Question

    Need Help in Real-Time?

    Connect with top rated Experts

    17 Experts available now in Live!

    Get 1:1 Help Now