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  • #2300713

    Not receiving external emails

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    by quintar51 ·

    Background info:
    I have a windows 2000 Active Directory Domain with service pack 3. I have one DC/DNS/EXCHANGE server. I’m running Exchange 2000 with service pack 3. I have a router with port 25 enabled for SMTP traffic. The same port is specified in Exchange as well.

    Problem:

    I am unable to receive External email ONLY. Also, I can send to hosts outside my network, but I can’t send INTO my network. I don’t get any errors or anything saying that the message is undeliverable.

    I’m not sure if DNS is the issue here, but I do have an MX record pointing to my email server, which is the 2000 server itself.

    Also, one important point. This exact setup did work in the past. I since rebuilt my server, but the setup is exactly the same.

    Does anyone have any suggestions?

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    • #3396398

      Not receiving external emails

      by quintar51 ·

      In reply to Not receiving external emails

      An update regarding my troubleshooting so far.

      I have an internet email account which I setup on one of my clients. This account uses smtp and pop3 traffic, and i’m able to receive email there. That means SMTP is going through, so the router isnot the problem.

    • #3396307

      Not receiving external emails

      by lordinfidel ·

      In reply to Not receiving external emails

      There are several places to check here.

      I normally don’t accept e-mails offline. But if you send an e-mail to lordinfidel@directionweb.com
      I can take a look at it externally and see where it is getting stopped.

      The areas that could be stopping it is
      1- firewall
      2- incorrect rules on firewall
      3- incorrect mx record
      4- no domain specified in exch

      As a point of record, you should not be running dns and exch (much less a AD DC) on the same machine.

      Although I do this for small clients, running dns and AD on the DC. It is actually not the reccomended way. It has to do with if DNS get’s corrupt and you reboot, and the DC can not register itself in DNS, AD will fail and it will become a contstant loop state.

      • #3396186

        Not receiving external emails

        by quintar51 ·

        In reply to Not receiving external emails

        Hi, thanks for the tip.

        I try installing exchange on a different machine and see if the problem is resolved.

    • #3392667

      Not receiving external emails

      by lordinfidel ·

      In reply to Not receiving external emails

      Let’s look at this logically before you go installing on a new machine.

      You said that prior to the new machine you had no problems.

      You built a new machine, changed the MX record and you can send but can’t receive.

      If nothing has changed onthe firewall, and the settings are exactly the same.

      And from the outside you can telnet into the server like so telnet machineIP 25

      Then the 1 place I would consider a culprit is DNS propagation.

      Start up a cmd prompt, start nslookup.type in set type=ns
      then att.com

      select one of their name servers IP’s and go
      server IP
      (This will change the NS that you are sitting on)

      Now set type=mx
      type in your DomainName only, ie mydomain.com

      What are the IP’s returned? Are theycorrect? If they are not correct then that is your problem. You need to see what the TTL is set for your records.

      If it *is* correct. Then you need to go from the outside and try to telnet into your mailserver. If you can’t then it is your firewall. Make sure that you are allowing new inbound from all above tcp 1024 to mail sever IP tcp 25

      If that is there, then make sure that you have specified your domains that exchange is responsible for.

      • #3392562

        Not receiving external emails

        by quintar51 ·

        In reply to Not receiving external emails

        hmmm I do think the problem is with the DNS like you’ve mentioned. Okay, I went through the steps you’ve outlined, and when I looked up my domain, it didn’t come back with an IP address. Instead it came back witH A weird answer. You can check by looking for rk-ane.com. That’s my domain. I think it’s something with zoneedit.com, which hosts my A and MX records. They point to my DNS server for email and WWW. I was sure I set up everything correctly there. See, if I run nslookup for my A record, it does come back with the correct IP.

    • #3392366

      Not receiving external emails

      by lordinfidel ·

      In reply to Not receiving external emails

      Found your problem. It is in DNS.

      Your MX preference is set to 0, it needs to be 20.

      I set it at 20 so if I have to add another sever in during a pinch, I can set it at 10.

      > set type=mx
      > rk-ane.com
      Server: internal
      Address: 192.168.0.1

      rk-ane.com MX preference = 0, mail exchanger = mail.rk-ane.com
      rk-ane.com nameserver = ns7.zoneedit.com
      rk-ane.com nameserver = ns14.zoneedit.com
      ns7.zoneedit.com internet address = 207.228.252.107
      ns14.zoneedit.com internet address = 209.126.159.80
      > set type=a
      > mail.rk-ane.com
      Server: internal
      Address: 192.168.0.1

      Name: mail.rk-ane.com
      Address: 216.126.89.102

      • #3392364

        Not receiving external emails

        by lordinfidel ·

        In reply to Not receiving external emails

        Also,

        C:\>telnet mail.rk-ane.com 25
        Connecting To mail.rk-ane.com…Could not open a connection to host on port 25 :
        Connect failed

        Which means that the mail server or firewall is actively rejecting connections to tcp 25.

        This needs to be opened at your firewall.

        from any tcp <=1024 to mail tcp 25 I can do a port scan, but unless I am sitting on your network, it will just be a bunch of false positives. if you were able to telnet to that port from internally, then it is not the mail server but the firewall. So you have 2 issues going on. 1 is DNS and the second is the port being opened.

      • #3395350

        Not receiving external emails

        by quintar51 ·

        In reply to Not receiving external emails

        Hi again. Regarding DNS: Now, I do have a MX record with the name servers, zoneedit.com. I can only make it either 0 or 10, can’t set it to 20. Also, on my DNS server, I need to have an MX record as well correct? Because my mail server is on another machine right? And that MX record, I can set to 20 for the preference.

        BTW, I will give you the points, just keep rejecting so you can add further answers. Thanks.

    • #3394161

      Not receiving external emails

      by quintar51 ·

      In reply to Not receiving external emails

      This question was closed by the author

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