Messaging Server: local DNS domain should include "localhost"

Question

I'm having problems with Netscape
Messaging Server (3 and 4) in environments with certain DNS configurations.
<P>
Most customers configure their systems to use the local hosts database (/etc/hosts file)
before using DNS to resolve hostnames to IP addresses.
<P>
Netscape Messaging Server uses its own custom hostname resolution software, and
generally ignores system configurations that use /etc/hosts. This can cause
problems if the Messaging Server were to look for information that is not in
DNS, but in /etc/hosts.
<P>
Netscape Messaging software will occassionally attempt a DNS lookup on
"localhost". If you do not have localhost entries in the search path, you
may see one of two problems:
<OL>
<LI>Sendmail Emulator will return spurious Couldn't connect to
<mailserver hostname> to deliver mail. error.
<P>
This problem will happen in Messaging Server 4.0, 4.0.1, 4.0.3. This problem is fixed in 4.05 and 4.1.
<P>
For example, if you typed the following:
<P>
#/usr/lib/sendmail -v [email protected]
Subject: this is a test message
test text
You might have received the following response:
<P>
sendmail: Couldn't connect to to deliver mail.
sendmail: Message saved in /dead.letter
<P>
<LI>smtp is very slow (15 seconds - 2 minutes) in returning banner.
<P>
This problem may happen with Messaging Server 4.1.
<P>
System/Mail Administrators:
<P>
Netscape Messaging Server will ignore /etc/hosts
and NIS in this case.
Adding localhost to your /etc/hosts
file or NIS hosts database will not
resolve this problem.
<P>
You can verify the source of this problem with nslookup:
<P>
(succesful test)
<P>
machinename.domain.com% nslookup localhost
Server: nameserver.domain.com
Address: 200.00.XX.XXX
Name: localhost
Address: 127.0.0.1
(failed test)
<P>
kwikimart.mcom.com% nslookup localhost.machinename.domain.com.
Server: machinename.domain.com
Address: 200.00.XX.XXX
*** machinename.domain.com can't find localhost.domain.com.: Non-existent
host/domain
<P>
Network/DNS Administrators:
<P>
A DNS entry for localhost should be created for any domain in the search
path of the messaging server. "localhost." exists in the root nameservers
on the Internet, so this problem should onnly occur in networks where the
following is true:
<OL>
<LI>Direct access to the internet root (.) is not available.
<LI>Internal DNS does not have an entry for "localhost."
</OL>
<P>
The simplest solution is to create a domain and entry for "localhost." or
add "localhost" to a domain in mail server's domain search path.
<P>
NOTE: Netscape Technical Support can explain what DNS entries are required
for Netscape products. Netscape Technical Support does not support or
configure DNS for customers. This includes BIND (named) and Microsoft DNS.
</OL>

Answer 1

I think I found the answer to your problem here.
To save you some trouble, here is the quote:
{quote}
Q: Names on the internet are working fine, but looking up local names
from /etc/hosts or DHCP doesn't seem to work.
A: Resolver code sometime does strange things when given names without
any dots in. Win2k and WinXP may not use the DNS at all and just
try and look up the name using WINS. On unix look at "options ndots:"
in "man resolv.conf" for details on this topic. Testing lookups
using "nslookup" or "dig" will work, but then attempting to run
"ping" will get a lookup failure, appending a dot to the end of the
hostname will fix things. (ie "ping myhost" fails, but "ping
myhost." works. The solution is to make sure that all your hosts
have a domain set ("domain" in resolv.conf, or set a domain in
your DHCP server, see below fr Windows XP and Mac OS X).
Any domain will do, but "localnet" is traditional. Now when you
resolve "myhost" the resolver will attempt to look up
"myhost.localnet" so you need to have dnsmasq reply to that name.
The way to do that is to include the domain in each name on
/etc/hosts and/or to use the --expand-hosts and --domain options.
{quote}