Quote:
Originally posted by PxT
It may even be a violation of your ISP's Acceptable Use Policy to insert fake headers -- which probably means you lose your net connection if your ISP finds you doing this more than once. (They know that the only people who _really_ need to do this are spammers...).
However, many people have Linux working at their homes as SMTP (sendmail) servers. We do not send mail through our ISP's server. We buy dial-up accounts just for getting Internet connections. Except for those Windows users, the rest (like Unix guys) prefer sending mails through their own **IX SMTP (sendmail) servers installed in their PCs.
So, mail header modification is now completely our own business and is not a violation of ISP policy.
But things are still hard. The recipients server anyhow knows the IP of the sender server and adds this portion into the email header when it receives a mail. The portion is like following,
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Received: from eddie_host.com([200.100.100.200]) by recipients_server.com (JetMail 2.5.3.0) with SMTP id jm03b8b2cb4; Mon, 27 Aug 2001 21:20:50 -0000
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What reports the IP of my sendmail server to the recipients server? Sendmail daemon? Does the recipients server resolve the IP form the network packets (Network Layer of OSI)? If we have to change something at the network layer to spoof the IP, I would like to give up.