[luau] RH7.3 Sendmail probs

[Erich Schrottke]

Hi Guys,

Thanks for all the advice on my post a couple weeks ago regarding redoing 
a new box.

I've made the plunge and installed RH7.3, and managed to successfully 
install a 'custom' setup. I let RH installer do mysql and PHP although my 
instinct was nagging me to hand install those. I have yet to install 
Apache and FP extensions. The RHN updates are kinda spiffy (first time 
I've tried it) and with VNC it's pretty nice to be able to log in 
remotely.

I'm excited about playing with squirrel mail and other toys once I've got 
the machine stabilized. I have a few more dumb questions to ask and there 
may be simple answers, but I'm not quite able to sort this out.

Situation:
==========
Initially the custom install put in IPCHAINS vs. IPTABLES contrary to RH 
documentation. I'm not familiar with either, but found that once I got up, 
that my DNS wasn't working (I do my own DNS for websharx.com and a couple 
of friends domains).

1 ) I did a bit of googling, and was able to figure out how to open up
port #53 to the outside world.

2) I then had a problem with mail not coming in and opened up SMTP, but
mail still was not coming in. Telnetting from the outside to mail port did
not work.

As a result the following lines were added to /etc/sysconfig/ipchains 
file:

-A input -s 0/0 -d 0/0 25 -p tcp -y -j ACCEPT
-A input -s 0/0 -d 0/0 53 -p udp -j ACCEPT

3) Mail still was not coming in and the port now showed on nmap scans but 
showed as being closed. After a little more googling, I commented out this 
line from the /etc/mail/sendmail.mc file:

dnl This changes sendmail to only listen on the loopback device 127.0.0.1
dnl and not on any other network devices. Comment this out if you want
dnl to accept email over the network.
dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')

After changing DAEMON_OPTIONS to have dnl in front of it, mail started 
coming in.

NOTE: Have I done something horrible and opened myself up more than 
necessary? I'd like to keep this puppy tight, but I need to serve DNS, 
WWW, and receive and send mail locally and from the outside.

4) I'm having a problem with mail being rejected from a host that I'm
sending mail to. I can send mail to some folks, but not others. This 
particular host returns the following message:

=======================================================================
The original message was received at Wed, 18 Sep 2002 01:26:46 -1000
from sharky at localhost

   ----- The following addresses had transient non-fatal errors -----
<xxxx at xxx.com>

   ----- Transcript of session follows -----
... while talking to smtp-cpf.xxx.com.:
>>> RCPT To:<xxxx at xxx.com>
<<< 451 4.1.8 Domain of sender address sharky at websharx.com does not 
resolve
<xxxx at xxx.com>... Deferred: 451 4.1.8 Domain of sender address 
sharky at websharx.com does not
resolve
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old

    [ Part 2: "Delivery Status" ]

Reporting-MTA: dns; tiger.websharx.com
Arrival-Date: Wed, 18 Sep 2002 01:26:46 -1000

Final-Recipient: RFC822; xxxx at xxx.com
Action: delayed
Status: 4.1.8
Remote-MTA: DNS; smtp-cpf.xxx.com
Diagnostic-Code: SMTP; 451 4.1.8 Domain of sender address 
sharky at websharx.com does not resolve
Last-Attempt-Date: Wed, 18 Sep 2002 06:26:15 -1000
Will-Retry-Until: Mon, 23 Sep 2002 01:26:46 -1000
=======================================================================

My DNS seems to be working and I basically copied the /var/named entries 
from my old RH6.2 setup over to the new one, and changed /etc/named.conf 
appropriately. Nslookup seems work inside and pinging from other hosts 
seems to work. Nslookup from the outside using websharx.com as the server 
work too.

I've believe I've changed the hostname in the right places, but not sure 
if that is the issue.

I have a feeling I'm missing something in my sendmail setup or my DNS 
setup that makes this host reject my mail. I can send mail to other hosts 
though, just like when I was on RH6.2. I used to send mail to this host 
regularly but with this install of RH7.3 it rejects it.

Would anyone be able to help me with learning this aspect of config or 
provide insight?

Any other tips you might suggest for this new install? I'm trying to keep 
only a minimum of ports open till I can get everything locked down.

Thanks in advance,
	Sharky