Edit: As of 8th December, 2012 Google no longer allows free registration to Google Apps account, which means these guidelines below can't be termed as **FREE** anymore.
Have you just recently bought a domain but don't own an custom email address for your domain ? Are you tired of changing configurations every time you change your domain registrar or hosting ? You do not consider changing your registrar fearing that you will loose your old emails ?
Well if any of the above question has a positive answer for you then here lies the solution...
Free email for your domain using Google Apps
Background: Google Apps provides 10 user accounts free "For individuals and small teams" with 10GB each of Inbox size, calendar, docs and other Google services1. Thus you can simply configure your domain's DNS settings (MX Records) and use Google's email service tied to your domain. The process is simple and requires 3 basic steps.
Book and register your domain with your favourite domain registrar.
Go to apps.google.com and register for a Free account, you would need to mention your domain here, say example "domain.com". The rest of the process is simple as registering your email id. Once you are done and able to login to your Google Apps account with the account you've just created you will be notified to verify that you actually own the domain before you can start using it. This step is easy if you are using any domain registrar which is a Google's affiliate (like, GoDaddy.com) else you might have to follow a few steps (mentioned there itself) to manually verify your ownership of the domain.
Now you need to configure the DNS settings (MX records) in your domain's control panel to use the Google Apps for email. Those who are not very proficient with this, let me tell you just look for the words "MX Records" and get in there. You might already find some entries present in there, make a note of those or just in case you change your mind later. Next you need to remove any existing entries and add the following entries there.
A typical MX Records table should look like below screens:
Have patience and wait for some time for the DNS settings to propagate across. It may take anything between 1 hour to 48 hours, but as per my experience it generally doesn't takes beyond 6 to 8 hours. To test simply try sending an email to your newly registered Google Apps id say "firstname.lastname@example.org" and open your Google Apps mail to see if it has reached there. Link to your Google Apps account should be https://mail.google.com/a/domain.com
Hope these tips helped you, don't forget to leave your comments here.