I am trying to set up sendmail on a Redhat 9.0 server and am having a problem with smtp connections being refused. In the security window it is set to allow smtp connections. If I type in 'nmap -sT -O localhost' it shows port 25 is being monitored for smtp connections. I have put in the entries I want in the /etc/aliases file and run newaliases. The Netscape mail program on my client PC can through POP3 retrieve messages sent from another account on the server using the mail command. If I type in iptables -L to show how the iptable rules loaded into memory, it shows that it is allowing smtp connections from everywhere. Something is blocking inbound e-mails from the internet and emails from my client PC that is set to use the Server as its smtp server for sending out e-mails. Any ideas?

If you system is running syslogd, (which I almost sure it is - default setting). Your system has been maintaining a log file for mail operations. With RH9, you will find this file as /var/log/mail. You can use a text editor to read this file (Note - Don't modify it. If you do it could cease logging for you). Read the lines for a specific piece of email. The ones that are being rejected should have a statement like (check_rcpt) or (check_mail). If it is check_rcpt (or check_rcpt), then try this -

Backup /etc/mail/sendmail.cf
Open /etc/mail/sendmail.cf with a text editor
Find a line that read something like this -

R$*. . . $#error$@ 5.7.1 $: "550 Relaying Denied"

and place a # in front the line. It should now read -

#R$*. . . $#error$@ 5.7.1 $: "550 Relaying Denied"

Save sendmail.cf
Restart sendmail using a terminal console and the command -

service sendmail restart

If it says anything else, reply to this post

Mike:

I took a look at the maillog file. It gets a new entry every time I try retrieving emails from the server. When ever I try sending an e-mail from the client (I have double checked that the SMTP server the client is pointing to is correct) no entries show up in the log. I suspect the setup in my iptables or something else is blocking the inbound smtp transactions.
I tried your suggested change to the sendmail.cf file and did the:

service sendmail restart

It didn't change the results. My client PC still gets the connection refused message.
THanks in advance for any more ides.

To go any futher, reply back with a few lines the mailog. Then we can take it from there.

Another question - Do you have your DNS running on your RH9 machine?

Mike:

the last entries in my maillog file are as follows:

Jul 8 04:08:02 mars sendmail[15182]: h6897pJc015182: to=root, ctladdr=root (0/0), delay=00:00:11, xdelay=00:00:10, mailer=relay, pri=30240, relay=[127.0.0.1] [127.0.0.1], dsn=2.0.0, stat=Sent (h6897qbH015184 Message accepted for delivery)
Jul 8 04:08:02 mars sendmail[15185]: h6897qbH015184: to=<root@mars.ldcglobal.com>, ctladdr=<root@mars.ldcglobal.com> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=local, pri=30896, dsn=2.0.0, stat=Sent
Jul 8 14:39:41 mars ipop3d[17735]: pop3 service init from 192.168.1.4
Jul 8 14:39:55 mars ipop3d[17735]: Auth user=eric host=[192.168.1.4] nmsgs=0/0
Jul 8 14:39:55 mars ipop3d[17735]: Logout user=eric host=[192.168.1.4] nmsgs=0 ndele=0
Jul 8 14:39:58 mars ipop3d[17736]: pop3 service init from 192.168.1.4
Jul 8 14:40:04 mars ipop3d[17736]: Auth user=eric host=[192.168.1.4] nmsgs=0/0
Jul 8 14:40:04 mars ipop3d[17736]: Logout user=eric host=[192.168.1.4] nmsgs=0 ndele=0

I do have named bind for DNS running. Is that what you mean by having DNS running?

Eric