qmail could not find host

Posted on 2009-04-17
Last Modified: 2013-12-02
I am receiving the folloing message ( I hid the .com name for confidentaility reasons:

Hi, this is the qmail-send program at I'm afraid I wasn't able to deliver your message to the following addresses. This is a permanent error; I've given up. Sorry  it sorry it didn't work out.
<>.  Sorry, I couldn't find any host named (#5.1.2)

***Below this line is a copy of the message

Recieved: (qmail 916 invoked from network)
Received: from unknown (
by ( with esmtp:
End of my typing the copy of the message.

If we send out 20 emails, possibly 2 or 3 of them come back with this message.  If we call the receipient, they some times have actually received the email eventhough we got the above message.

Please advise.

Question by:bob733
    LVL 57

    Accepted Solution

    This appears to be a DNS resolution issue.  I would suggest that you verify that the qmail server is pointing to the correct DNS servers.  You should also do a dig or nslookup on the host names you get the errors on.

    Either there is no such host name, or the qmail server is timing out attempting to resolve the host name.  The timeout could be caused by various reasons.

    LVL 20

    Assisted Solution

    by:Daniel McAllister
    You may want to look at the DNS record for the target domain (

    try this: dig mx

    The above should be the ENTIRE part after the @ in the TO part of the email address.

    This should return something like this result:

    ; <<>> DiG 9.3.4 <<>> mx
    ;; global options:  printcmd
    ;; Got answer:
    ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50246
    ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 3, ADDITIONAL: 0

    ;                    IN      MX

    ;; ANSWER SECTION:             14400   IN      MX      0             14400   IN      MX      0

    ;; AUTHORITY SECTION:             172800  IN      NS             172800  IN      NS             172800  IN      NS

    ;; Query time: 303 msec
    ;; SERVER:
    ;; WHEN: Wed Apr 22 10:04:57 2009
    ;; MSG SIZE  rcvd: 153
    This output shows that has 2 mail servers (with very long domain names), and that it was discovered using one of 3 DNS servers for that domain (all at

    I hope this points you in the right direction...


    Author Closing Comment

    The Problem turned out to be the ISP (Comcast)!  In effect they were not allowing all the emails to be blasted out (1000), emails (invoices), unless the user upgraded their Comcast subscription!  They can not leaglly block all the emails so they get around it by rendomly screwing up some of them.  Don't you love it?
    Thanks anyway guys.  I have just split the points for your efforts!

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