Postfix -- Mail relay issue

Discussion in 'Installation/Configuration' started by tonysch, Feb 15, 2009.

  1. tonysch

    tonysch New Member

    I have been running this Ubuntu 6.06 (ISPconfig, Postfix) server for over 2 years now. I followed your "Perfect..." docs. I must say, the best around... Thank you.
    About a month ago I started receiving sporadic emails that my server had been spamming.... My VSP notified me the other day and I have been going through my configs for the last 3 days now.

    I have a Virtual Server out on the internet with my own public IP. I am hosting about 5 websites. Only 3 of them use mail. 2 of them are using my server as the the SMTP relay for their mail client.

    I was wondering if someone could point me in the right direction?

    here is my postfix

    # Debian specific: Specifying a file name will cause the first
    # line of that file to be used as the name. The Debian default
    # is /etc/mailname.
    # myorigin = /etc/mailname

    smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
    biff = no

    # appending .domain is the MUA's job.
    append_dot_mydomain = no

    # Uncomment the next line to generate "delayed mail" warnings
    # delay_warning_time = 4h

    # TLS parameters
    smtpd_tls_cert_file = /etc/postfix/ssl/smtpd.crt
    smtpd_tls_key_file = /etc/postfix/ssl/smtpd.key
    smtpd_use_tls = yes
    smtpd_tls_session_cache_database = btree:${queue_directory}/smtpd_scache
    smtp_tls_session_cache_database = btree:${queue_directory}/smtp_scache

    # See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
    # information on enabling SSL in the smtp client.

    myhostname =
    alias_maps = hash:/etc/aliases
    alias_database = hash:/etc/aliases
    myorigin = /etc/mailname
    # mydestination =,, localhost
    relayhost =
    mynetworks =
    mailbox_command = procmail -a "$EXTENSION"
    mailbox_size_limit = 0
    ### Limit sent/recieved emails to 100 Megs "(header+body+attachment)x(mime-encoding) <= 100 meg"
    message_size_limit = 102400000
    recipient_delimiter = +
    inet_interfaces = all
    inet_protocols = all
    smtpd_sasl_local_domain = $myhostname
    smtpd_sasl_auth_enable = yes
    smtpd_sasl_security_options = noanonymous
    broken_sasl_auth_clients = yes
    smtpd_recipient_restrictions =
    smtpd_tls_auth_only = no
    smtp_use_tls = yes
    smtp_tls_note_starttls_offer = yes
    smtpd_tls_CAfile = /etc/postfix/ssl/cacert.pem
    smtpd_tls_loglevel = 1
    smtpd_tls_received_header = yes
    smtpd_tls_session_cache_timeout = 3600s
    tls_random_source = dev:/dev/urandom

    virtual_maps = hash:/etc/postfix/virtusertable

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

    Any help would be greatly appreciated.
    Thank you
  2. till

    till Super Moderator Staff Member ISPConfig Developer

    1) Test if your server is a open relay:

    2) If thats not the case, then your problem is most likely not related to the postfix or mail system setup, it is just a vulnerable contact form script or cms system that is misused to send spam.

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