RE: Sendmail not able to send to external addresses.

[Jason Dixon <jason dixongroup net>]

On Thu, 2003-07-31 at 16:20, Cleveland mail winnefox org wrote:
> > You didn't answer my last question, so I did a little 
> > investigation of my own.
> 
> Sorry, forgot about that one. What exactly is a PTR?

Pointer record.  It's a DNS record that allows for the mapping of an IP
address back to a hostname.  It's not necessary for normal operation on
the Internet, but it is/can be required for certain applications.  Many
mailservers are configured to reject mail from other servers that do not
have reverse DNS (PTR) in place.  Also, kerberos authentication requires
a valid PTR.  It appears that you are authoritative for your subnet, so
you can add it yourself.

On a side note, I noticed that your SOA has incorrect syntax for the
contact email address:

176.242.199.in-addr.arpa. 10800 IN      SOA     axp.winnefox.org.
boehning\ winnefox org  2003021202 14400 7200 12096000 86400

You should use "boehning.winnefox.org".

> > Fortunately (for me), your DNS 
> > provider is allowing zone transfers to outside parties 
> > (BAD!).
> 
> What does that mean, and how can I fix that?

It means that anyone is allowed to pull a complete copy of your DNS
zone.  This is bad.  You shouldn't allow zone transfers.  Check your
nameserver manpages for the proper syntax to disable this option.

> > An axfr of winnefox.org shows 2 mail servers, "mail" 
> > and "storm".  A quick check of storm's IP shows no PTR in 
> > place.  Fix that and your problems disappear.  :)
> 
> Actually, Storm is the redhat 8 server that's been working fine for
> about 6 months now. The new server is Mystique.

I see no DNS in place at all for "mystique".  Is this in the
winnefox.org domain or something else?

-- 
Jason Dixon, RHCE
DixonGroup Consulting
http://www.dixongroup.net