[TriLUG] re: Sendmail question

[Turnpike Man]

Is the named service running and DNS configured with your forward and reverse
zones??  The command "nslookup -sil set q=mx yyy.com" didn't work for me
either.  I was able to get a proper response by doing this at prompt:
nslookup <enter>
set type=MX <enter>
example.com <enter>

and the response was:
example.com mail exchanger = 10 host.example.com.

More Info:
I fought with a sendmail issue myself last night.  I just rebuilt my home
server from RHL 7.2 to 9, here's where my problems were:

1.  sendmail.mc: I thought I didn't do a good job of configuring sendmail.mc
based on the file I saved myself and notes I took, I was actually ok there, I
thought, so I moved on.

2.  DNS and "reverse" DNS:  I could send email with pine to myself at
example.com and I could send email outside my network to anotherexample.com.  I
could NOT receive email from any other domain but my own.  Finally after going
through error messages, repeating and repeating the problem, and asking a
couple people questions, it came to reverse DNS.  The discovery came when I was
trying to telnet to me.example.com 25.  It kept failing, but telnet localhost
25 was working beautifully.

I use internal DNS at home, just as if a corp network.  My forward zone was
seemingly working, but I had failed to verify my reverse zone.  I finally got
DNS working again (I actually used redhat-config-bind for a change instead of
vi).  I couldn't telnet to me.example.com 25 still.

3.  I had missed something in sendmail.mc:

dnl DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl

That line needs to be commented out (that's the dnl part at front of line
instead of #) unless you only want to send email to and from yourself, iirc.  I
had missed commenting this line.  Now I seem to be fine, I have tested myself
to make sure I don't have an open relay, thanks Tanner, and my emails are
flowing.

(Also, I'm a RR customer, I don't seem to have any problems emailing AOL or RR
users.  :)  That snippet is for those of you who read this far!)

So, HTH!
David M.


--- Tom Raleigh <tlenc2003 at yahoo.com> wrote:
> Thanks Dave and Jon for your responses. 
>  
> Here is the content of the /etc/resolv.conf:
>  
> domain yyy.com
> nameserver 192.168.123.123
>  
> (The IP address 192.168.123.123 is the correct IP for DNS server.)
>  
> When i issued the command: nslookup -sil set q=mx yyy.com, I got "connection
> timed out: No servers could be reached" error.
>  
> I am surprised because sendmail server and DNS server are on the same AS21
> box now.  Telnet to localhost 25 is OK with the welcome message appearing
> just fine.
>  
> Regards,
> Thanh


__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com