smtp port other than 25

Discussion in 'Installation/Configuration' started by acumen, Nov 16, 2009.

  1. acumen

    acumen New Member

    some of my client's port 25 blocked by their ISP. So, i want to add one more listen port to postfix. What's the best way?

    1. can I change postfix conf file manually? master.conf? how? or,
    2. I use ispconfig's firewall, can i also use iptables to redirect the additional port to 25?

  2. damir

    damir New Member

  3. acumen

    acumen New Member

    ammm... what I want to do is, setup another port to redirect to port 25. Not the one smtps.

    If I use ISPConfig's firewall, can I also setup the redirect just like iptables?

    iptables -t nat -A PREROUTING -p tcp --dport 9925 -j REDIRECT --to-ports 25
  4. radim_h

    radim_h Member HowtoForge Supporter

    All you have to do is go to /etc/postfix/ and uncomment
    lines about submission and smtps.

    Then you will be able use port:

    25 - also with TLS Enctyption
    465 - also with SSL Encryption
    587 also with TLS Encryption

    Don't forget allow these port in firewall if you use dome...

    # Postfix master process configuration file. For details on the format
    # of the file, see the master(5) manual page (command: "man 5 master").
    # Do not forget to execute "postfix reload" after editing this file.
    # ==========================================================================
    # service type private unpriv chroot wakeup maxproc command + args
    # (yes) (yes) (yes) (never) (100)
    # ==========================================================================
    smtp inet n - - - - smtpd
    submission inet n - - - - smtpd
    -o smtpd_tls_security_level=encrypt
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject
    -o milter_macro_daemon_name=ORIGINATING
    smtps inet n - - - - smtpd
    -o smtpd_tls_wrappermode=yes
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject
    -o milter_macro_daemon_name=ORIGINATING
  5. TheBirdMan

    TheBirdMan Member

    SMTPs SSL/TLS secure?


    I was wondering if someone could help me verify the security of smtps. I have configured Postfix (with ispconfig2) to use pop3s, Imaps and smtps port 645. The maillog shows they are all using TLS and thunderbird picks up the cert for ( When I use wireshark however smtps is using TCP not TLS. Is there something beyond my understanding going on? STARTTLS maybe?


  6. falko

    falko Super Moderator ISPConfig Developer

  7. TheBirdMan

    TheBirdMan Member

    Thank you,

    Now I can sleep at night. :)

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