host name lookup failure

[Kevin Darcy]

jon.ingason at equant.com wrote:

> I am trying to send e-mail from a host behind fire wall.
> It har worked untill recently and I have not change
> anything on this host. The fire wall is configured so
> it is open out, but only allowing connection on port
> 53 (DNS) and 80 (WWW). If I try to send to join at global-ip.net
> I get following in my log:
>
> Jul  4 10:43:47 stat2 sendmail[26932]: [ID 801593 mail.info]
> g637FRi2004695: to=3D<join at global-ip.net>, delay=3D1+01:28:20, xdelay=3D=
> 00:00:00,
> mailer=3Desmtp, pri=3D9210343, relay=3Dglobal-ip.net., dsn=3D4.0.0, sta=
> t=3DDeferred:
> Name server: global-ip.net.: host name lookup failure
>
> Ok, I now use dig to see if I can looked it up:
>
> dig global-ip.net mx
>
> ; <<>> DiG 9.2.1 <<>> global-ip.net mx
> ;; global options:  printcmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 57358
> ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 2, ADDITIONAL: 4=
>
> ;; QUESTION SECTION:
> ;global-ip.net.                 IN      MX
>
> ;; ANSWER SECTION:
> global-ip.net.          86400   IN      MX      10 mail.global-ip.net.
> global-ip.net.          86400   IN      MX      20 pop.global-ip.net.
>
> ;; AUTHORITY SECTION:
> global-ip.net.          86400   IN      NS      ns.global-ip.net.
> global-ip.net.          86400   IN      NS      nic2.global-ip.net.
>
> ;; ADDITIONAL SECTION:
> mail.global-ip.net.     86400   IN      A       194.52.1.14
> pop.global-ip.net.      86400   IN      A       194.52.237.244
> ns.global-ip.net.       86400   IN      A       194.52.1.10
> nic2.global-ip.net.     86400   IN      A       194.52.237.242
>
> ;; Query time: 11 msec
> ;; SERVER: 194.52.1.10#53(194.52.1.10)
> ;; WHEN: Thu Jul  4 11:14:01 2002
> ;; MSG SIZE  rcvd: 172
>
> This seems OK, so what is the problem? I can't see it.
> Can you?

You should point "dig" at what resolver your mail server is using, if you
want to accurately mimic the way it resolves Internet names. My guess would
be that some sort of firewall issue is at the bottom of this problem. (By
the way, if only ports 53 and 80 are open, how are you going to make an
outgoing SMTP connection?)


- Kevin