Need help to configure sendmail

[Zbigniew Koziol]

Frank Peng wrote:
> I am using Sympatico at my home computer.
> 
> I do not have a static IP address. I update my IP
> address if it is changed so you can always get my web
> site at www.familywebhouse.com.
> 
> I thought sendmail should be the same as httpd. Since
> I am running sendmail and listening on port 25(I can
> telnet it locally), why I cannot listen to outside?
> How Sympatico block this? How do they know you are
> connecting me with port 25 since the name could be
> resolved and you can reach this IP address?
> 
> I did not understand. Thanks a lot!

This becomes a little boring.

They "know" that you try to connect on port 25. Actually, their 
servers/routers "know". They rather do not care about "you".

Connecting to a remote place means not only sending IP address, but also 
port number. You can not "connect" by using IP adress only.

So, they blocked port 25, which is used for sending mails by your mail 
server, sendmail. They allow only that you connect their own server at 
that port.

zb.

--
Zbigniew Koziol, SoftQuake^(tm) Open Source Business Solutions
Toronto, Canada, http://www.softquake.ca, info-lcEyp1+e+UdAFePFGvp55w at public.gmane.org
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