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.