Comcast blocks spam loophole

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Affects but just a bit.

> Comcast's home customers should be connecting to
> Comcast's servers to send E-mail. Typically
> that would be on POP3 port 110, not SMTP port 25.

Can anyone explain to me how POP3 is used to send email? I read RFC 1939 (http://www.faqs.org/rfcs/rfc1939.html) and didn't find a clue. AFAIK POP3 is used only to receive email. SMTP to send. (see also: http://computer.howstuffworks.com/email4.htm)

> My networks are configured to allow only SMTP
> servers to connect outbound on port 25;
> there's no reason why ISP's shouldn't do the same

Of course there is! Some of their customers need to connect to their independent email provider's SMTP servers on port 25. An email client (such as Outlook Express) sends email by connecting to an SMTP server, that is by default configured to listen to port 25. They can usually use the ISP's SMTP server to send email instead of their independent provider, or their provider can configure the SMTP server to listen to an additional port, or to use SSL connection to the SMTP server that is by default on another port.

Posted by: hadaso   Posted on: 06/11/04 You are currently: a Guest | Members login | Terms of Use

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