postfix is on openrelay

Discussion in 'Installation/Configuration' started by matehortua, Sep 30, 2005.

  1. matehortua

    matehortua New Member

    I installed a suse 9.3 box with the exellent falko guide (the perfect setup)
    then i installed ISPconfig and is working without problems.... at this moment

    my only problem is that my mail-server POSTFIX is on openrelay (sending mail to other domains) and that is very bad.

    what can i do to fix this problem???

  2. falko

    falko Super Moderator Howtoforge Staff

    Why do you think it is an open relay? If you have followed the tutorial then it should not be an open relay.
  3. matehortua

    matehortua New Member

    i think an Open Relay is when th mail server (postfix) sends mail from any domain to any destination.

    i think it should restrict the sending of mails to:

    mydestination = /etc/postfix/local-host-names

    but is not...

    i have this line also on the
    relay_domains = $mydestination

    can you tell what is the appropiate way to enable on my server the sending of messagges ONLY to my local-host-names??

    a lot of tanx
  4. falko

    falko Super Moderator Howtoforge Staff

    There are 3 cases where your server accepts emails without authentication, but is still not an open relay:
    1) You're sending directly from your server, i.e. you're logged in on the server, e.g. on the shell or with a webmail interface.
    2) You're sending an email to a recipient who is on the server.
    3) You're sending from within a network that is specified in the mynetworks variable in /etc/postfix/

    If one of these 3 points applies, and you're wondering why you don't need to authenticate: this is normal and does not mean your server is an open relay.

    Can you run
    telnet localhost 25
    and then issue
    ehlo localhost
    and post the output here?
    If you see a line starting with 250-AUTH then it should be fine.
  5. matehortua

    matehortua New Member

    #telnet localhost 25

    ehlo localhost
    250-SIZE 10240000
    250 8BITMIME

    mmm i didnt see the 250-auth but when i installed (new) it was there ..... :(
    i know i didnt change anything except the changes that ISPconfig did.

  6. falko

    falko Super Moderator Howtoforge Staff

    Then do the Postfix configuration again. It's here:

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