When you choose to use Gmail for your POP3 email client instead of using a POP3 email client (like Thunderbird, Outlook etc… some) email programs show both your Gmail address and your POP3 email’s address.

I do this at work because I prefer Gmail for its superior spam protection, and because when I want to access my email I don’t have to be at my home or office, and I don’t need to worry about transferring emails, settings and such every timwe I get a new computer. So at myemail@gmail.com I get email from mywork@myjob.com, and until now some email programs would show my emails as:

From myemail@gmail.com on behalf of mywork@myjob.com

Not so cool, but now I don’t have to face that.

Read the Gmail blog post that explains how to do this…
New Gmail POP3 settings