Folks,

I have a remote sever and a LAN, here my story onlcy concerns the LAN

This LAN has a redhat 9.0 server and with a bunch of Win and Redhat clients.

The Redhat 9.0 server has 2 ethernet cards, one for the internet,
one servers as squid proxy, thx to squid, internet access is fine with
all clients

Now I use old sendmail at server side, and it's just fine

The problem is with my client side, I use Mozilla 1.6 as mail client,
to test Mozilla mail client works, at sever side, I configure
Mozilla's outgoing mail server as my 2nd card Ip address:
192.168.0.1, and sending email out from the server is just fine
(telnet 192.168.0.1 26 is also fine, in /etc/hosts I use 192.168.0.1
as IP address instead of 1st card's real IP address or 127.0.0.1);
now at client side, I have some trouble, I've got following questions:

1. why telnet 192.168.0.1 25 from client fails

2. is that a squid problem? I heard of that problem - if yes,
but at least telnet 192.168.0.1 25 should work (I stopped squid,
telnet 25 still does not work)

Thx,
HTM

It sounds like a firewall problem - what rules do you have?
iptables -L

It may be worth checking that sendmail is listening to all interfaces:
netstat -nlp

Yeah, you are right, once I relaxed my firewall rules, now at my client side,
I can telnet 25 port of my local server, however, send mail at Mozilla 1.6 after
configuration still failed, the error info is as flows:

Error occurred during sending email, mail server response:

5.7.1 <farfromcrowded@yahoo.com> ... Relaying denies, IP
name lookup failed [192.168.0.2}

Here my local server has 2 ethernet cards, 1 for internet, another for
squid proxy: 192.168.0.1

and 192.168.02 is my client

If that is squid problem? If yes, how to resolve it?

Thx,
HTM

You will need to configure relaying:
http://sendmail.org/tips/relaying.html

So far you've helped me on resolving 2 problems:

1. del 127.0.0.1 issue
2. sendmail in a LAN

If possible, could you take a look at my posted problem at my remote server side
on imap issues?

On my local LAN side, I have no prblems now except mailman setup

Really apreciate your kindest help and most generous help.
HTM