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Spoofing local addresses

Discussion in 'E-mail Discussion' started by Bruno Morais, Apr 27, 2018.

  1. Bruno Morais

    Bruno Morais Member

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    Hello,
    Maybe this was already answered but I couldn't find a solution to my problem.
    I have shared hosting with several accounts. Lets imagine I have domain.com in my server with SPF and DKIM configured.

    So now from a remote PC I can telnet port 25 and can send an email with headers from and recipient that exists in the server:

    Connected to mail.domain.com.
    Escape character is '^]'.
    220-mail.domain.com ESMTP Exim 4.89_1 #1 Sat, 28 Apr 2018 00:47:23 +0100
    220-We do not authorize the use of this system to transport unsolicited,
    220 and/or bulk e-mail.
    helo mail.com
    250 mail.domain.com Hello xxxxxxxxxxxxxx [111.111.111.111]
    mail from: user@domain.com
    250 OK
    rcpt to: user@domain.com
    250 Accepted
    data
    354 Enter message, ending with "." on a line by itself
    aaaaaaaaaaaaaa
    .
    250 OK id=1fCD5t-0003RC-AF

    So if I configure an email client to spoof the email it will work.
    What configs should I put in Cpanel to avoid this?
    Thanks in advance.

    Regards,
    Bruno Morais
     
  2. cPanelLauren

    cPanelLauren Forums Analyst II
    Staff Member

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    Hello @Bruno Morais

    There are a few things you can do to avoid spoofing.

    - add an SPF record which delegates IP addresses and hosts that are able to send mail for a domain. Our SPF documentation can be found here: Authentication - Version 68 Documentation - cPanel Documentation
    - Set the account to bounce mail for unrouted addresses. If you're accepting mail for unrouted addresses it may be possible to accept spoofed mail. Documentation on this can be found here: Default Address - Version 68 Documentation - cPanel Documentation

    Thank you,
     
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