backend server can't send mail to internet

Posted on 2006-05-25
Last Modified: 2008-03-06
Dear all
In our organisation we have 1 domain controller with dns enabled, and on that dns forwader is disabled because i disable root hints.
now i install newly exchange server (backend connect with LAN , Front end connect with internet) now i am able to receive emails, but not be able to send it, what action i will take , so that backend server is able to send an email outside.


Question by:khaled_mct

    Author Comment


    it's good idea to use simple dns plus ok or ???
    LVL 104

    Expert Comment

    The backend can usually send email fine. Unless told otherwise the server will try and send email on its own.

    The first thing you should try is a full nslookup and then telnet test:

    For example...

    Default Server:

    > set type=mx

    Non-authoritative answer:   MX preference = 10, mail exchanger =   MX preference = 10, mail exchanger =   MX preference = 10, mail exchanger =     internet address =     internet address =     internet address =     internet address =     internet address =     internet address =

    When you have the MX server information, see if you can telnet to port 25 of the remote server.

    For example (using the above information)
    telnet 25

    If any part of that test fails, then you have a problem.

    If the nslookup fails, then it is your DNS configuration.
    If it is the telnet test, then you have a connectivity issue.
    Try it from the frontend server as well.

    You have mentioned that you have made changes to the DNS on the server.
    For name resolution to work you should use either root hints, or forwarders. If you have removed both, then the server may have a DNS problem. DNS forwarders will usually be your ISPs DNS Servers - that is what I do as it provides the best performance. The root hints can be left in place, as with forwarders configured they will not be used.


    Author Comment

    ok i fix the error but some time exchange server able to send mail to  internet like
    ((yahoo hotmail and other domain)) and some time
    server!!!not able to route mail to internet i check my dns it's ok any other reason or any good way to check exchange server dns work fine to route mail to internet

    LVL 104

    Accepted Solution

    The procedure I wrote above confirms DNS and connectivity to the Internet - and whether the machine can connect correctly.

    The quickest resolution is to use an SMTP Connector to route the email via your ISP.

    The problem with intermittent issues is that they are intermittent and difficult to track down. You need the NDR messages generated - not the delay messages, but the fatal failure messages.


    Author Comment

    thanks you it's all work now just i have problem in hotmail..thw way you was very nice

    Featured Post

    Highfive Gives IT Their Time Back

    Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

    Join & Write a Comment

    Find out how to use dynamic social media in email signatures with this top 10 DOs & DON’Ts.
    Not sure what the best email signature size is? Are you worried about email signature image size? Follow this best practice guide.
    In this video we show how to create an email address policy in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Mail Flow…
    how to add IIS SMTP to handle application/Scanner relays into office 365.

    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

    22 Experts available now in Live!

    Get 1:1 Help Now