DNS issue

Kerberos Posts: 3 Spectator
edited January 10 in Internet 2023 Archive


I am facing issue with my own personal email server: some senders got rejected due to non-resolvable domain names. For example:

Maillog contains following:

NOQUEUE: reject: RCPT from unknown[]: 450 4.7.25 Client host rejected: cannot find your hostname, []; from=<support@portmone.com>...

When I do nslookup on the same machine, I get:


** server can't find SERVFAIL

I don't use any DNS servers except of provided by Spectrum. Any ideas?


  • Lyn_T
    Lyn_T Posts: 419 ✅ Verified Employee Moderator

    Good evening @Kerberos

    Thank you for reaching out to us in regards to your DNS issues with your personal email server. Unfortunately, this is a third party product and we would not be able to offer troubleshooting for this concern. You can try to clear the DNS cashe. If this doesn't help I recommend reaching out to the email service you are using for additional troubleshooting. - Lyn

  • RAIST515O
    RAIST515O Posts: 103 Contributor

    May ultimately want to setup dynamic DNS service with someone, considering your IP with Spectrum can potentially change without notice. This way you can better ensure you have a domain name that can always point back to your IP to properly route your traffic.

    Asus has support for their service built into some of their routers... other brands may have a similar setup as well (if you are using your own router).

  • Kerberos
    Kerberos Posts: 3 Spectator

    Yeah, I know about DDNS (setting it up right now), but the problem is in the portmone.com (3rd party domain) itself - it seems to be misconfigured - no reverse DNS at all.

This discussion has been closed.