I’ve been using GMail as my primary mail client for some time now and have walked a number of people through these steps. For these steps to work, you will need to be able to have your email address (ie. firstname.lastname@example.org) directed to your GMail box (email@example.com).
[Update 9/4/2010: Sorry, in the move to a new hosting provider all the screen shots that should be in this post were lost.]
- Log in to GMail
- Click Settings
- Click Accounts
- Click Add Another Email Address
- Enter your Name and Email Address
- Click Send Verification
- Verify your email address
- (Optional) You can set this email address to be your default within GMail on the Accounts page by clicking make default.
- (Optional) You can also change your Reply-To settings to use your default email address or to use whichever one the original email was sent to. I have mine set to use the original.
Hope that helps. Contact me if you have any questions on this.