I'm using:
thunderbird-10.0.3-1.el6_2.x86_64 on Scientific Linux 6.1
and if I send an e-mail (with Gmail) from my Thunderbird then I can see that the e-mail I sent contains a very-very bad thing:
Received: from [192.168.1.142] (31-149-121-34.pool.myisp.com. [31.149.121.34]) So ALL the e-mail that I'm sending containst my NATed IP address + my public IP address.
Can I delete/remove these lines, so that they will be aren't in ALL the e-mails that I send??
UPDATE: if I send an e-mail with the gmail web interface, then:
Received: by 10.112.129.10 with HTTP; Sat, 14 Apr 2012 09:20:13 -0700 (PDT) Aren't there any Thunderbird Add-ons that modifies my IP Address in the e-mail?
Received:headers: they show the trail of where did the message pass through. That's how email works. Your only chance is convincing the mail server not to disclose your IP (I guess this may be difficult), or use some anonymization service. Of course stuff sent through a web interface won't have your IP address underReceived, because it does not originate from your computer, but from the web server.