Email not delivered to mailbox

Discussion in 'Server Operation' started by J Paul, May 18, 2018.

  1. J Paul

    J Paul New Member

    I have email not being delivered from specific domains. I have turned off anti-virus / spam filtering for the receiving email. Incoming email shows in log as follows:
    May 18 10:27:01 renmus postfix/smtpd[9031]: NOQUEUE: filter: RCPT from unknown[##.##.##.###]: <>: Sender address triggers FILTER amavis:[]:10024; from=<> to=<> proto=ESMTP helo=<>
    May 18 10:27:01 renmus postfix/smtpd[9031]: NOQUEUE: reject: RCPT from unknown[##.##.##.###]: 450 4.7.1 <>: Helo command rejected: Host not found; from=<> to=<> proto=ESMTP helo=<>
    Is there a way to correct this?; reverse server lookup appears to be preventing delivery. How can I allow for this domain to pass?
    Thank you in advance for your assistance.
  2. ISPConfig Developer ISPConfig Developer

    it can't find the host "" right? is it something like your internal exchange-server with some domain not real for the outside world? Add it to the /etc/hosts file or change the authentication, use port 587 tls and auth before sending.
    or delete the reject_invalid_host ( something like that, off the head ) value for senders, which might be bad.
    J Paul likes this.
  3. J Paul

    J Paul New Member

    Thanks for the help - you got me on the right path.
    Removed the following smtpd_helo_restrictions: reject_invalid_hostname, reject_non_fqdn_hostname, reject_invalid_helo_hostname, reject_unknown_helo_hostname.
    I don't know if this is good practice as their hostname does not resolve to an IP address. I hope that I am not introducing trouble on my end to accommodate someone else's issue. If anyone has a comment on this change, please comment.
    Thanks again.

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