How to hide your private IP in Mozilla Thunderbird

In Mozilla Thunderbird, when you send an email, the IP address of your computer is included in the email headers. The information contained in the header looks something like this:

Received: from 192.168.1.10 ( xxx.mysite4now.com [123.123.155.63] )

where 192.168.1.10 is the IP of the computer from which you have sent the email.

Of course, this is not very convenient as it shows private info about you. But it this there for a reason. Some anti-spam solutions request your private IP address in order to let your email pass over. The good news is that there is a workaround: you can setup Mozilla Thunderbird to show a random IP address instead of your real private IP. Let’s see how!

As Mark M Manning  shows in his article, you can hide your your IP address in Mozilla Thunderbird this way:

1. Open Mozilla Thunderbird
2. Go to Preferences -> Advanced -> General
3. Click on Config Editor
4. Type in ”smtp” and find the number of the SMTP server you want to adjust (usually it will say smtp1)
5. Right click on the table and create a new string
6. Name it mail.smtpserver.smtp*.hello_argument,  where * is the number of the SMTP server settings that you’re changing. Usually 1
7. Setup your fake IP to whatever value you want (e.g. 123.25.1.10)

Important: By changing your real private IP to a fake IP your email will be more likely be marked as spam by anti-spam filters.

After you perform these steps the headers of emails you sent will contain the IP you have setup:

Received: from 123.25.1.10 ( xxx.mysite4now.com [123.123.155.63] )

It’s that simple! Enjoy!