1. Please take a little time for this simple survey! Thank you for participating!
    Dismiss Notice
  2. Dear Pleskians, please read this carefully! New attachments and other rules Thank you!
    Dismiss Notice
  3. Dear Pleskians, I really hope that you will share your opinion in this Special topic for chatter about Plesk in the Clouds. Thank you!
    Dismiss Notice

Spam relaying via Plesk postix Mail Server

Discussion in 'Plesk 9.x for Linux Issues, Fixes, How-To' started by PaddingtonC, Aug 31, 2012.

  1. PaddingtonC

    PaddingtonC Basic Pleskian

    Jan 24, 2012
    Likes Received:
    I have a Plesk 9.5 mail server on Ubuntu 8.04 LTS which forwards all SMTP traffic to an anti-spam server cacti.snowbarre.co.za. Many times I see the headers on the anti-spam server to contain from addresses not hosted on the mail server and I have checked and confirmed that my server is not an open relay server. How can a spammer be using my server to relay spam traffic? How can I stop this?

    Open relay test:
    paddington@paddington-MS-7387:~$ telnet cm 25
    Trying 196.201.x.x...
    Connected to cm.
    Escape character is '^]'.
    220 cm.snowbarre.co.za ESMTP Postfix (Ubuntu)
    mail from:test@facebook.com
    250 2.1.0 Ok
    221 2.7.0 Error: I can break rules, too. Goodbye.
    Connection closed by foreign host.

    A typical headers is:
    View basic headers
    Received from cm.snowbarre.co.za (cm.snowbarre.co.za[196.201.x.x]) by cacti.snowbarre.co.za (Postfix) with ESMTPS id 00B601881AD; Mon, 27 Aug 2012 14:03:29 +0200 (SAST)
    Received from cm.snowbarre.co.za (localhost []) by cm.snowbarre.co.za (Postfix) with ESMTP id 81627367E007; Mon, 27 Aug 2012 14:02:50 +0200 (SAST)
    Received from User (ml82.128.x.x.multilinksg.com [82.128.x.x]) by cm.snowbarre.co.za (Postfix) with ESMTP; Mon, 27 Aug 2012 14:02:49 +0200 (SAST)
    Reply-To <amsnkeuri@ymail.com>
    From "Ms Nkeuri Aguiyi"<admin@jogor.net>
    Subject Your Unpaid Fund.
    Date Mon, 27 Aug 2012 05:03:22 -0700
    MIME-Version 1.0
    Content-Type text/html; charset="Windows-1251"
    Content-Transfer-Encoding 7bit
    X-Priority 3
    X-MSMail-Priority Normal
    X-Mailer Microsoft Outlook Express 6.00.2600.0000
    X-MimeOLE Produced By Microsoft MimeOLE V6.00.2600.0000
    X-Antivirus avast! (VPS 120821-0, 08/21/2012), Outbound message
    X-Antivirus-Status Clean
    Message-Id <20120827120250.81627367E007@cm.snowbarre.co.za>
    To undisclosed-recipients:;
    Last edited: Aug 31, 2012