How to Enable telnet?
 

I have Fedora 9 running as Sendmail Server. I tried to telnet from client machine but reported error like:

Server : 10.14.73.50
Client: 10.14.77.33

FROM CLIENT MACHINE:

FROM SERVER MACHINE:

I tried running :
I dont see Port 23 Open.
That means telnet is not enabled. How Can I enable telnet in my Fedora 9 Box?

1. Install the telnet server:

2. Enable it:

But ... you really don't want to use telnet for anything serious. Use SSH instead, for anything but intranet fun & games.

I am using telnet for checking sendmail connectivity.
Do You have other way around apart from this?

You don't need a telnet server for this. You already have the client and that's it.
You're trying to connect to it too.
telnet IP PORT(25 is sendmail/SMTP)
But your connection gets refused by sendmail for some reason, not because you don't have telnet server installed.

When you run nmap, run it as:
nmap -p 25 10.14.73.50
not localhost, nmap the same IP as you're trying to connect to SMTP.

Thanks Tux-Slack !!!

I tried running from client:

What could be the reason?
Whenever I send mail through sendmail as:
#echo "hello" | mail -v -s "hi" tuxbuddy@gmail.com

It works !!!

But Why Dont client recognize the server.

Because that way it tries to send mail over localhost and it works.
I bet your sendmail is listening only on 127.0.0.1
Paste output of command:
netstat -avtpn | grep 25
And your sendmail.mc file.

Or wait, just look for a line similar to:
DAEMON_OPTIONS(`Port=smtp,Addr=0.0.0.0, Name=MTA')dnl
in your sendmail.mc file.
Addr=0.0.0.0 means that the server will listen on all machines network interfaces.
If you want to send mail over your server only from your internal network then change Addr=0.0.0.0 to:
Addr=Servers-Internal-IP
I think it's this one 10.14.73.50 right?
But if you want to send mail over your mail server from outside of your network then leave it 0.0.0.0, but in that case be double sure you're not an open relay.
You can test it with some of these tools
And make sure that your firewall(iptables) allows traffic over TCP port 25 on local and/or public network.

Here is the output:
Now I have added as you said and now the output becomes:

Are you sure you ran that on the mail server?

Sorry I posted before refreshing.

Now Its Working !!!
Thanks Tux.

Now it shows:

One Last Query..

Say, Sitting on Client I want to send mail to a user called abhi on the Server.
How can I do that?

I forgot one thing tho. Sowwee.
Now sendmail wont listen on the localhost.
Minor fix. Just add another line reading:
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

Rebuild .mc file, restart sendmail and both should now work.


To send a mail through your server you need to configure a mail client application, such as thunderbird, add a outgoing SMTP server(your server local IP, port 25 and use proper authentication). Don't know exactly how to send mail with sendmail command from a client, never tried it.

Don't know exactly how your server is configured, but to get a little better idea, I suggest reading through Slackware SMTP AUTH HowTo. You can skip the installing part, because you've already got the MTA installed, and the configuration is pretty much the same deal on all systems running sendmail. It will give you a better insight on how sendmail or should I say, how any MTA works. If you wont understand anything, I will be more than happy, as I'm sure anyone else will be, to answer any possible questions regarding the configuration.

In one of the Other Server its not showing :

Done.

Thanks Tux for Fix.

You can't check for listening ports with netstat over network, you need to use nmap to check open ports, but it can be a bloat, perhaps the daemon is listening for the "outside world" but the firewall might be blocking it, so it's always better to check on the server that's running the daemon for listen addresses and ports, because it doesn't matter how much the firewall is blocking it.

I ran the nmap on Machine 10.14.16.215(new Server) and it showed:
No Idea why its Not showing :25.
I checked with these commands: