firewall IP as Originating IP for emails

[Dave Ihnat]

On Thu, Sep 09, 2004 at 04:50:18PM +0630, Mrs. Geeta Thanu wrote:
> 554 5.7.1 The server sending your mail[210.212.212.2] does not have a
> reverse DNS entry.connection rejected.Please conatct your network ISP
> provider.Default reject!

This used to be a common rejection, when each site was assigned its
own IP address(es).  It then became less common, as assignment of IP
addresses from ISPs became the norm.  Now, it appears that some sites,
in a probably misguided attempt to reject spammers, have returned to
trying to validate IP addresses.  I say misguided since (a) most spam
is from owned machines, so it won't help, and (b) most admins won't have
arranged with their ISPs--and many ISPs aren't willing to--provide PTR
records that reflect the originating domain.

Basically, it's a DNS setup issue.  You have a DNS A record or records in
your zone file associating your domain with your IP address.  There is
supposed to be a corresponding PTR record that, given an IP address,
results in your domain name being returned.  Instead, it's certain that
the PTR record either points to the ISP's domain name or--as I don't
get an answer when I do a "dig any -x" on the IP address you gave in
the example, assuming it's really your IP address--there isn't any PTR
record at all.

The message says it all--talk to your ISP.

Cheers,
-- 
	Dave Ihnat
	ignatz at dminet.com