In the course of doing business with "Company X" we received a bounce saying
they no longer accept mail from us. Digging deeper brought this fairly extreme
reponse:
[quote]
Company X has implemented a number of anti-spam measures that
require adherence to standards and best practices with regards to the
sending server and message content.
One of the measures is to block direct-MX connections from dsl, cable
and dial-up networks. In your case, the reverse DNS entry for your
server's IP address is "h-66-166-42-108.dnvtco56.covad.net". We block
all connections from ".covad.net". This does not effect the normal
Covad mail servers.
There are a couple easy solutions to this blocking. The first is to
relay through your ISP's server. If your server is connected with a
Static IP address, your ISP may be willing to update the reverse DNS
entry for that IP to specify that it is your mail server. The second
solution is ideal, but not always available.
If you have any other questions, please do not hesitate to contact an
administrator via email at emailhelp(_at_)udlp(_dot_)com(_dot_) That address
is not
subject to the blocking.
[/quote]
My initial reaction was
1) SPF + Reputation Based System beats "just shut off all DSL."
2) Relay - no way, it just complicates things
3) Change the DNS - wow, is this a common thing to do?
So, is this a common thing? Is this idea gaining ground?
In a world with spf1 what's a good reponse to this?
Got SPF - anybody got a good reputation based system?
Jon B.