I noticed K-9 Mail (Android), Geary, Sylpheed and Thunderbird are leaking my personal and private IP in the email headers.
I know web clients like gmail don't suffer from this problem. But what can I do to avoid my IP leaking while using desktop/mobile apps. Are there any options/configurations available to protect this information? Any clients that implement this by default or have a option in the settings.
Received: from [192.168.0.XXX] (dhcp-255-255-64-255.my.isp.com [255.255.64.255]) by smtp.gmail.com with ESMTPSA id xxxxxxxxxxxxxxxxxxxxxxxxx for <firstname.lastname@example.org> (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Jan 2017 20:13:49 -0800 (PST)