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Require Authentication to Send Emails To Owned Domains

Discussion in 'E-mail Discussion' started by Juanpi, Feb 14, 2019.

  1. Juanpi

    Juanpi Registered

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    Location:
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    cPanel Access Level:
    Website Owner
    My server is allowing emails to be delivered without authentication, and I am pretty sure this is one of the reasons we are getting lots of emails from our own email addresses.

    A simple telnet smtp proves this to be the case.

    $ telnet myserver.com smtp
    Trying XXX.XXX.XXX.XXX...
    Connected to myserver.com.
    Escape character is '^]'.
    220-server.myserver.com ESMTP Exim 4.91 #1 Thu, 14 Feb 2019 18:44:58 +0000
    220-We do not authorize the use of this system to transport unsolicited,
    220 and/or bulk e-mail.
    HELO myserver.com
    250 server.myserver.com Hello yyyyyyyyyyyyyyyy XXX.XXX.XXX.XXX]
    mail from: john@myserver.com
    250 OK
    rcpt to: john@myserver.com
    250 Accepted
    data
    d354 Enter message, ending with "." on a line by itself
    Hello
    .
    250 OK id=1guM0c-0000qF-AP


    How can this be prevented?

    Attempting to send emails to other domains like brooke@removed.tld returns 550 Authentication Required, so AFAIK this means my server is not an open relay.
     
    #1 Juanpi, Feb 14, 2019
    Last edited by a moderator: Feb 14, 2019
  2. cPanelMichael

    cPanelMichael Technical Support Community Manager Staff Member

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