sendmail: unable to qualify my own domain name

[James Pletcher]

As a result of a takeover, our site had to change it's IP scheme. We changed all the "hosts" file entries and modified the netconf entries for "IP_ADDRESS", "BROADCAST_ADDRESS", and "ROUTE_GATEWAY" then re-booted. All went well except during boot we got a message saying "local host name () is not qualified; fix $j in config file". Each time a process attempts to send an email alert, user "root" gets a message saying, "{hostname} sendmail [{pid}]: unable to qualify my own domain name ({HOSTNAME}) -- using short name" and an error email is sent to root that contains the line, "SMTP;501 5.0.0 HELO requires domain address".

Rookie needs help!

[Mel Burslan]

did you change the ip address of this host in the /etc/hosts file after you updated the ip address ?

looks like the address resolution of the servername itself on this server is not resulting the right name.

check any references of old ip address in the /etc/hosts or /etc/mail/sendmail.cf

also from the command prompt, when you run:

nslookup $(hostname)

what output do you get ? Old or new IP address ? and where is this address coming from ? does it say "using FILES" or "using DNS" ?

[Camel_1]

Is the mail server outside your firewall? Does your server has NAT address?

Perhaps you need to add an entry to the mail server relay.

[Rick Garland]

This typically points to the entry in the /etc/hosts file.

Include the FQDN in the /etc/hosts file as well as the short name.

[James Pletcher]

"hosts" has the correct address. The nslookup (without the "$") works and returns the correct ip and says "FILES". When I do nslookup and answer {hostname} in the dialogue, it says FILES and return the correct address.

[Mel Burslan]

as Rick suggested, in the /etc/hosts file, do you have both the shortname and the fully qualified domain name associated with the same ip address on the same line ?

[James Pletcher]

This has been working up until now with no problems. DNS is in the same place, mailgate (MTA) has not changed.

[Steven E. Protter]

After changing the hosts file, you may wish to have this server join a valid DNS server in your organization with /etc/nsswsitch.conf changes to make DNS the second choice for name resolution.

This should alleviate the error condition.

SEP

[James Pletcher]

The name service is set to hosts then DNS then NIS (whatever that is).
In my hosts file I did not ahve an "alias". Does that metter? The line reads:
10.11.12.80 {tab} HOSTNAME

[John Dvorchak]

One check to make is that nslookup returns the Fully Qualified Domain Name. I have always used the following format for /etc/hosts. The first line after the comments is the loopback i.e.

127.0.0.1 localhost loopback

then the very next line should have the box FQDN name listed first then the alias or short name.

192.1968.1.11 server.yourdomain.com server

Remember /etc/hosts is read from top to bottom to putting the loopback and correct FQDN and alias first insures that you will resolve the proper address.

[Rick Garland]

In the /etc/hosts file, have the full, long name as well as the short name

IP address FQDN short name
1.2.3.4 mysys.mydomain.com mysys

The short name would function as an alias in this case.

The nsswitch.conf file can look something like this (I am only listing the line for 'hosts');

#hosts: files [ NOTFOUND=continue ] dns
#hosts: dns [ NOTFOUND=continue ] files

Depending on whether you want to resolve by FILES or by DNS, both examples are included.

If using DNS, have the FQDN listed 1st followed by the short name.

The nslookup should return the FQDN with alias of the short name.

[Mel Burslan]

sometimes, depending on the configuration of sendmail, by sendmail.cf file, fully qualified domain name is required. And kicker is, sometimes it is not. sendmail.cf file is still a mistery to me in its entirety, therefore, I can not even fathom understanding yours even if you post it here, but it won't hurt if you append the FQDN to the HOSTNAME in your /etc/hosts file in my opinion.

[SGUX]

isn't this the small problem which can be solved by putting a . (dot) behind the hostname-entry

[Mark Ellzey]

James,

If you are running NIS, you will need to do a couple of things. First verify that the proper host name (FQDN) and IP address is in your /etc/hosts file. Then make sure you do a /var/yp/ypmake. Also, check your /etc/nsswitch.conf file. If you have NIS as the first entry, and have not rebuilt (ypmake) your NIS maps, the lookup will still return the old hostname and IP address.

Regard,
Mark

[Tom Smith_9]

Have you tried configuring the "Dj" directive in sendmail.cf?

Ex. Djmydomain.com