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bigchris
Do Not Shoot The Messenger
Premium,MVM
join:2002-04-29
Leesburg, VA
reply to koitsu

Re: [Spam] Comcast reporting spam from my IP

Comcast will not provide you the logs or evidence of why you were blocked. Having worked at hotmail you can understand why, it's not only an issue of storing private information but also a question of subscriber base size. It would simply be impossible to provide that evidence for the size of user-base.

Comcast treat spam over any port with equal distaste, despite what the abuse rep said. However, with port 25 being open with no AUTH requirement it's significantly easier for a spammer to utilize that port rather than 587 or 465. The reason is obvious and it's that they need to know a valid username and password which requires a lot more work on their end.

Finally, you are probably right in the cause of the block. i.e. you were reported as sending spam.

Just move to 587 with AUTH (or 465 AUTH and SSL if you can).


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23
said by bigchris:

Comcast will not provide you the logs or evidence of why you were blocked. Having worked at hotmail you can understand why, it's not only an issue of storing private information but also a question of subscriber base size. It would simply be impossible to provide that evidence for the size of user-base.

Comcast treat spam over any port with equal distaste, despite what the abuse rep said. However, with port 25 being open with no AUTH requirement it's significantly easier for a spammer to utilize that port rather than 587 or 465. The reason is obvious and it's that they need to know a valid username and password which requires a lot more work on their end.

Finally, you are probably right in the cause of the block. i.e. you were reported as sending spam.

Just move to 587 with AUTH (or 465 AUTH and SSL if you can).
*nod* Thanks for the clarification. I've migrated to prt 587 (postfix + Cyrus SASL for SMTP AUTH). Port 465 is a pain due to extra reliance on stunnel, since postfix doesn't natively support port 465 any longer.

An interesting experiment -- and I am not condoning or advocating this in any way, as it's shady -- would be to send Comcast some mails with forged Received: headers to see if they rely solely on the report, or if they do go back through SMTP server logs to correlate the claims.


bigchris
Do Not Shoot The Messenger
Premium,MVM
join:2002-04-29
Leesburg, VA
I'm not going to comment on what we would or wouldn't do, but I guess I'd question why you'd want to bother with it. You now have a working solution so why mess with it.


odog
Cable Centric Vendor Biased
Premium,VIP
join:2001-08-05
Atlanta, GA
kudos:16
reply to koitsu
Check your IP here

www.senderbase.org


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC
said by odog:

Check your IP here

www.senderbase.org
To what end? He is sending from his IP address only to the Comcast SMTP message submission server. Comcast is only going to be concerned with whether he is an authenticated Comcast user, and acting within the limitations of the Comcast Terms of Use. Message submission servers shouldn't care about that Senderbase data.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum


odog
Cable Centric Vendor Biased
Premium,VIP
join:2001-08-05
Atlanta, GA
kudos:16
Reviews:
·Comcast
said by NormanS:

said by odog:

Check your IP here

www.senderbase.org
To what end? He is sending from his IP address only to the Comcast SMTP message submission server. Comcast is only going to be concerned with whether he is an authenticated Comcast user, and acting within the limitations of the Comcast Terms of Use. Message submission servers shouldn't care about that Senderbase data.
senderbase also gives a "score" about how much spam has been received from the particular IP. It more importantly will list if he is one of the large blacklists for whatever reason.


NormanS
I gave her time to steal my mind away
Premium,MVM
join:2001-02-14
San Jose, CA
kudos:12
Reviews:
·SONIC.NET
·Pacific Bell - SBC

1 recommendation

said by odog:

senderbase also gives a "score" about how much spam has been received from the particular IP. It more importantly will list if he is one of the large blacklists for whatever reason.
What does his IP address have to do with anything?!?!? He is sending through 'smtp.comcast.net'. The only thing which a gateway mail server should concern itself with is the IP address of 'smtp.comcast.net'. The Comcast user's IP address is not a part of the equation.

Look; just because I am running an MTA, doesn't meant my ISP IP address is connecting to gateway mail servers when I send out email. Neither his Comcast connection, nor my AT&T connection are a part of the equation! When we send through our respective ISP SMTP message submission servers, our IP addresses should be treated no different than any other users IP address while going through those servers.
--
Norman
~Oh Lord, why have you come
~To Konnyu, with the Lion and the Drum