Confused on SMTP IP address

Discussion in 'General' started by manatsu, Jan 26, 2010.

  1. manatsu

    manatsu New Member

    Hi there, I been using ISP2 switched to ISP3 6 months ago. Amazing system. We use it for our gaming clans and our home business.

    Lately we took on a challenge that utilized phplist to send newsletters for our local community. We are seeing some kind of issue with how outbound IP is handled. here is the scenario

    For example Server has 3 external IPs

    0.1 was the first external IP to be installed on the server while the rest was added on later.
    We set a domain called ABC.COM on 0.1, add email and everything, setup rdns and the domain works perfectly.

    Now we setup another domain called XYZ.COM on 0.2, setup email and setup rdns. But however, large email servers like yahoo and aol would often not take our emails. Mainly because when the server is connecting out to send the email, its sending with 0.1 IP address, which RDNS back to ABC.COM, and not XYZ.COM

    Is there anyway to have the smtpd server utilize the correct domain IP and use that to connect outside? I do not believe it is possible to set rdns of more than 1 domains on 1 IP?

    any help would be greatly appreciated.
  2. till

    till Super Moderator Staff Member ISPConfig Developer

    You have to add the line:

    smtp_bind_address =

    in postfoix and restart postfix. the configure the rdns record for this IP address so that it matches the hostname of your server.
  3. manatsu

    manatsu New Member

    I issue is that when i want to send email from both domains, there isn't a setting for the smtp server to pick the right IP to use to send based on domain name right?

    so if

    ABC points to 0.1
    XYZ points to 0.2

    both email outbound will be using same IP of 0.1?
  4. till

    till Super Moderator Staff Member ISPConfig Developer

    This is the normal behavipour of mail servers. mail servers never send email under a specific domain, they send all emails under their own hostname, it does not matter how many other virtual domains you have. So make sure that you configure it as I described above and it will work with yahoo and hotmail.

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