win1 - cl2 on black list

Discussion in 'Email Support' started by cdog, Jul 22, 2010.

  1. cdog

    cdog Perch

    A customer was suddenly unable to have emails sent from their shopping cart using smtp authentication via cdosys.
    Changing to an alternative port fixed the problem. Tech supports answer when I pointed this out was that the standard smtp port is checking blacklists. Further investigation found the web server ip on a blacklist and caused the problem.
    So it appears to me that Jodos webserver is being blocked by Jodos mailserver due to the fact that there is no rDNS for the web server IP as stated in the blacklist report given by spam cannibal.
  2. Stephen

    Stephen US Operations Staff Member

    we do no rDNS webserver IPs and as long as using SMTP Auth, it should not be needed as the mail server sending the mail is rDNSed.

    We do not rDNS the webserver IPs for a number of reasons.

    their action for blocking mail for no rDNS on the non sending part would be about like blocking it because an ISP doesn't do rDNS on a client IP....it really doesn't make sense if it is not the sender.
  3. cdog

    cdog Perch

    Thanks Stephen
    That was exactly the conversation I and my partner had when troubleshooting this, Made no sense to us either given that using smtp auth wouldn't work when email was sent via port 25 from the web app. Changing the sending port resolved the issue.

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