Re: [tlug] (OT) Reverse DNS resolution blues- ISP recommendations?

[Curt Sampson <cjs@??>]

On Wed, 7 Mar 2007, Brett Robson wrote:

> ...but Scott, Godwin and I have said that reverse domain name lookups
> are important and that many (most?) email servers will reject or flag
> as spam emails originating from servers with dodgy hostnames.

And yet I have two servers with PTR records that you say qualify as
quite "dodgy", I send a fair amount of e-mail to a wide variety of
recipients world-wide, and I am simply not experiencing this problem at
all. How do you explain this?

> That is exactly the problem Scott is having.

I am not yet ready to accept that. He's never even posted here the
messages that the SMTP servers are returning when they block his mail,
and in my experience these are quite frequently misinterpreted, when
interpreted at all. (My experience includes over ten years of running
SMTP e-mail systems and debugging issues with them, and four years of
hands-on running of a consumer- and small-business-oriented ISP.)

This is, for example, from the limited evidence posted here, quite
consistent with his IP address being in a dynamic IP block list, which
would have nothing to do with the contents of the PTR record for his
address.

> Many networks won't even let you send email from your server 
> (blocking outgoing port 25) forcing you to send via their email server....

Indeed. I don't see how this is relevant, though, since it's evidently
not the case here, for me or for Scott.

> Every system is different and your own personal experience is pretty
> well irrelevant.

I don't see why it's irrelevant. What is irrelevant is the mail system
run by the ISPs we buy connectivity from, since neither of us is using
them; both of us are delivering directly to the mail servers of other
systems that have no relationship with our ISPs except that they happen
to have IP connectivity with them.

I look forward to a more clear explanation of why, if the content of PTR
records is so important, and we both have "dodgy" ones, I simply do not
experience this problem.

cjs
--
Curt Sampson       <cjs@??>        +81 90 7737 2974