While here at work on my WinXP machine, I was checking the headers of an e-mail I received from my home account on my Linux (Fedora Core 3) machine at home. I'm using Evolution as my home e-mail client, and the machine is behind a NAT router (Linksys). Configured as a normal POP client - not using a local MTA like sendmail.

I'm not an e-mail nor a security guru, but I guess I shouldn't have been shocked to see that Evolution plasters my home PC's made-up host/domain name and the private address (192.168.xx.xx) as well as the official host/domain and IP provided by my ISP:

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Received: from 192.168.xx.xx
(my-dhcp-supplied-hostname.isp.com[123.456.789.123])
by my-isp.net (asdfqwerty) with SMTP id <2004121623033601400mmb4ne>;
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Since e-mail headers can easily be forged, how can I configure Evolution to protect my privacy a little better - I can be honest and have it put in just my public hostname/ip address. Since I have a NAT router, am I being paranoid about publishing the actual addresses of the PC's behind it? I have both Linux and WinXP PC's at home.

Right now the router is blocking all incoming requests, but I sometimes allow SSH, HTTP, and SSL through to the Linux system. I guess I could configure SSH to disallow user/password authentication and only use digital certs.

Any advice?