sendmail configuration / FQDN problem?

[Michael Gross]

Hello

I'm getting this message in my syslog:
Mar 26 11:21:46 D270 popper[25739]: (v2.1.4-R3) Unable to get canonical name of client, err = 0

I tried several tipps from another thread, but I can't get rid of the messages.

my resolv.conf contains the line:
domain foo.de

nslookup returns:
Name Server: D270.foo.de
Address: 192.1.2.6

Trying DNS
Name: D270.foo.de
Address: 192.1.2.6

my sendmail.cw:
localhost
D270
D270.foo
D270.foo.de
d270
d270.foo
d270.foo.de

/usr/lib/sendmail -d0.4,37.1 returns:
============ SYSTEM IDENTITY (after readcf) ============
(short domain name) $w = D270
(canonical domain name) $j = $w.foo.de
(subdomain name) $m = foo.de
(node name) $k = D270
========================================================

and there are no messages in the /var/adm/syslog/mail.log which seem to belong to the syslog.log messages.

Any further suggestions?

Thank

[Clemens van Everdingen]

Hi,

If you are using DNS you should check de fully qualified names of your clients, otherwise try to put fully qualified names in your host file to see if message is going away.

How is your nsswitch.conf configured ?

C.

[Steven Gillard_2]

This error is being reported by 'popper', which is probably some kind of POP3 server you have running on your system - its not related to sendmail.

It's likely that this POP server is attempting to reverse lookup the IP address of clients that are connecting to it, but is failing to get an answer. Do you know which clients connect to this system as a POP server? Do their IP addresses resolve correctly?

Regards,
Steve

[Michael Gross]

Further information to my problem:


nslookup 192.1.2.6 returns:
Name Server: D270.foo.de
Address: 192.1.2.6

Trying DNS
Name: D270.foo.de
Address: 192.1.2.6


nslookup D270 returns:
Name Server: D270.foo.de
Address: 192.1.2.6

Trying DNS
Non-authoritative answer:
Name: D270.foo.de
Address: 192.1.2.6

Is there anything wrong with my DNS?

Thanks for your help
Michael

[Michael Gross]

If there is any client connecting to the POP3 server, which is not known to the DNS, I will get this Error?

If yes, forget the problem ... I think I've got work to do ;-)

Michael

[Steven Gillard_2 · Accepted solution]

Thats what I suspect is happening - you have clients out there with IP addresses that can't be resolved through DNS.

Regards,
Steve

[Clemens van Everdingen]

Hi,

That's exactly what I meant in my first response.

Good luck.
C.