I am including this article into the EC2 section even it does not have anything to do with EC2 services but it is one of those things you will need once your application is up and running.
You will need two services in order to make this work.
Google apps
You will need to set the Google Apps so you can access your email through their interface. I have created support@getquantify.com for my application which sits on domain name http://getquantify.com. You can sign up in here to create your google apps account.
DNS Records
The second step you will need to do is to setup the name servers so your domain name is recognized and the emails know where they should go to. I am using free service for this – http://freedns.afraid.org. Create a free account and follow the instructions bellow.
Create CNAME Record. It should look something like this – mail.getquantify.com (G) CNAME ghs.google.com.
This record will allow you or your users to access the email over domain name mail.getquantify.com. You will need to add this information in google apps inside “Service settings” ->”General” -> “Web address”.
You also need to setup couple of MX records. It will look something like this – getquantify.com (G) MX 20:alt1.aspmx.l.google.com
Google apps will provide you with all the addresses you will need for your MX records. I have got 8 of them. You will find all the necessary information inside “Serice settings” -> “How to activate email” -> “Set up email delivery” -> “Change MX records”