Conflicts as to what is considered spam are indeed quite common as Barry points out. I disagree with another poster that there's a lack of transparency here, based on much of the information disclosed at http://postmaster.comcast.net, the fact that senders like DynDNS can and do signup for a mail Feedback Loop to see why messages are being rejected, that we regularly meet face-to-face with large senders to discuss deliverability at forums such as the Messaging Anti-Abuse Working Group (http://www.maawg.org), etc.
Also, we often hear of situations where a user might configure a forwarding service to mark email as spam / forward all spam, but on our system they do not have a spam folder setup, meaning they want us to block / drop the spam. So we do what the user tells our system to do in these cases, but a forwarding service is upset that we didn't accept the mail since the user did not configure their forwarding system similarly. These can become complicated situations, which is why we make an effort to work closely with senders and why the email industry as a whole continues to examine standards-based approaches to better securing email, and preventing spamming and phishing. Regards Jason Livingood Comcast -----Original Message----- From: [EMAIL PROTECTED] on behalf of Barry Gold Sent: Tue 10/14/2008 5:11 PM To: NNSquad Subject: [ NNSquad ] Re: Comcast Mail Blocking Issues Related to DynDNS >> From: "David P. Reed" <[EMAIL PROTECTED]> >> Date: October 14, 2008 1:45:19 PM EDT >> To: David Farber <[EMAIL PROTECTED]> >> Subject: Comcast blocking mail to its customers >> >> I am a happy user of DynDNS's Mailhop BackupMX service. Just got >> the following related to Comcast's blocking of inbound mail from >> DynDNS's Mailhop Forward service. Wholesale blocking of all mail >> intended for customers from a particular intermediate distributor, >> merely because they route it through an external service that adds >> value. >> >> While this doesn't affect me personally, it represents a "reach" on >> the part of Comcast. The "Mailhop Forward" service allows a user to >> have mail directed to him personally at another domain ([EMAIL PROTECTED]) >> to be directed to his comcast.net mailbox. As such it is like the >> "forwarding" that I do with my MIT Media Lab mail to my "reed.com" >> mailbox (hosted on a service provider). I find myself wondering if Comcast is blocking _all_ mail from Mailhop, or only mail for users who have a setting that block "spam" (as Comcast defines spam, which clearly isn't the same as the way Reed prefers). Conflicts in what is considered "spam" can be quite common, as ISPs attempt to apply heuristics to figure out what is spam and what isn't. This is never as good as the actual human looking at the headers and deciding. Too bad Comcast doesn't provide a "whitelist" service, where Reed could say, "yes, I want to receive mail from DynDNS, regardless of what your software thinks." Now if I could just figure out what piece of errant software is adding [[!!SPAM]] and [[??Probable Spam]] to my incoming mail. Time Warner claims it isn't _their_ server. I use Spam Assassin at my Nyx account, but only a small percentage of my mail routes through there (and _none_ of my Yahoo! groups mail, which are often so mislabeled). And I wouldn't expect Thunderbird to be doing it -- AFAIK T-bird puts a little flame next to mail that it thinks is spam. Oh well...
