How do I hide my IP address when I send email to somebody?
When I get questions like this, I always wonder what you are sending that you don’t want to be identified with. I’m going to continue with my answer assuming that you are not going to use the information for anything illegal, immoral or would otherwise make your mother unhappy were she to learn about it.
When you send an email, even if you don’t have your name in the send line, your IP address is still traceable. If you want to be completely anonymous, you need to take some extra steps to hide your identity.
Disposable Email Account
There are several levels of anonymous emails. For example, if you wanted to report your neighbor for overwatering his lawn during a drought but don’t want to cause hard feelings should the e-mail circulate, the easiest way is to just set up a “disposable” email account. Rather than use your personal account, you just set up another one, using any user name you want without putting your true personal information in as you set it up.
Remailers
If you want to send an email that is more anonymous than simply using a different account, you need to turn to a third-party remailer. When you use a remailer, you send an email to the remail service, they strip it of the header and IP information and send it on to the recipient. Again there are different levels of anonymity depending on the service you use and what you need the service to do for you. Keep in mind that these services track your IP address and report any illegal activity.
GnuPG
For ultimate anonymity, you will probably need to use PGP, which stands for Pretty Good Privacy, or the newest incarnation GnuPG. This uses public-key cryptography that hides the public key to a username and/or email address. The new programs use a combination of this and a hierarchal approach based on certificate authenticity.
We understand that privacy is a concern which is why we also recommend ParetoLogic Privacy Controls. While it’s not an IP cloaker, this tool does clean up your Web history files and offer a variety of controls valuable to any computer user, anonymous or not. Hopefully this information was helpful to you. Use it wisely.

Yes and no. IP addresses are unique addresses of network adapters that are used to identify computers on a network - and the Internet is one vast network. Most Web sites capture a variety of information about site visitors including browser type, operating system, and IP address.