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.