[wplug] reverse DNS

[Bill Moran]

Duncan Hutty wrote:
> Thank you all for your reponses.
> 
> <Bill Moran>
> 
>>1) Does the hostname resolve?
> 
> Yes
> 
>>2) Does the IP of the server have a PTR record
> 
> Yes, some foo-bar.client.comcast.net
> 
>>3) Does the hostname that comes back from a PTR lookup resolve forward?
> 
> Yes, the above foo-bar.client.comcast.net resolves to the correct IP address.
> 
> And yet, even hotmail.com mail servers tag any mail sent as spam!

But it's not rejecting it, right?

This is why I don't like content filters.  They do things like:
Most spam comes from hosts with names that start with numbers, this email came from
a host with a name that starts with numbers, thus this mail is likely spam.

Of course, this is going to generate both false positives and false negatives.

Exactly what heuristics hotmail is using to "tag" spam is beyond me, but this is part
of the reason that I'm heavily against content filters.  Of course, the real solution
is to stop playing nice with spammers and force mass-market ISPs like Comcast to
actually do something about spammers.  This is also the most difficult thing to
accomplish.

> Oh the irony! Does this imply that there is something else that I have incorrect
 > and it is not being tagged as spam/refused due to incorrect DNS?

I doubt it.  I'll bet any amount of small pocket change that the reason you're
being tagged as spam is because your PTR record has numbers in the first part.

> I appreciate the comments about Comcast's Evilness, and I need about one more
 > important/inconvenient outage/screwup to persuade my boss that a T1 is worth it.

You're not the only one.  I have a client who will be dropping Comcast as soon as
the sorts out a deal with one of their competitors.

> I could give a long list of reasons why Comcast is awful, but let's just leave
 > it at this: they have changed my company's STATIC IP address block 3 times in
 > the last 8 months. Does wonders for your VPNs that does, I can tell you.

Makes me wonder what these people are thinking?  "Hmm ... let's renumber our whole
IP space, just for the hell of it"?

-- 
Bill Moran
Potential Technologies
http://www.potentialtech.com