General discussion

  • Creator
    Topic
  • #2322116

    SMTP Relay

    Locked

    by a_tank ·

    I have inherited an email system that I am having trouble with. They have Exchange 5.5 set up on there LAN. All mail is forwrded to an SMTP server, running IIS 4.0, that sits outside of there LAN which is used to forward messages for the Exchange server. I am now receiving emails saying that this machine is forwarding Spam. Sure enough, the Mailroot\Queue is full of junk mail. As I am unfamiliar with IIS, how can I restrict this from happening. The IIS machine has the latest service packs. The Eschange Server does to, although the machine itself has only service pack 5. Any help appreciated.

All Comments

  • Author
    Replies
    • #3416885

      SMTP Relay

      by vinnyd ·

      In reply to SMTP Relay

      your exchange server is being used as an open relay.

      To test to see if it is you can go to this web site.

      http://ordb.org

      You submit your exchange server IP address and they will check it for you.

      Here is a web site with instructions on how to stop the relay.

      http://rr.sans.org/email/open_relay.php

      • #3583367

        SMTP Relay

        by a_tank ·

        In reply to SMTP Relay

        The question was auto-closed by TechRepublic

    • #3416883

      SMTP Relay

      by [_rick_> ·

      In reply to SMTP Relay

      Remove the IIS Server with the SMTP gateway and install an Exchange 5.5 server with the IMS Connector. (If you already have one – you can install another in a different site).

      The Exchange server can then be configured to restrict any relaying except from the Internal system.

      If you don’t want to use Exchange, then I recommend using a firewall which has SMTP relaying capabilities built-in or use a SENDMAIL product (either for Linux/Unix or for NT). These will provide you with better security and be more robust than the SMTP gateway found in the IIS environment.

      • #3583368

        SMTP Relay

        by a_tank ·

        In reply to SMTP Relay

        The question was auto-closed by TechRepublic

    • #3583366

      SMTP Relay

      by a_tank ·

      In reply to SMTP Relay

      This question was auto closed due to inactivity

Viewing 2 reply threads