To use Google Apps for email, you’ll have to configure your domain’s MX records to direct your email flow to Google’s mail servers.
Go to the DNS Editor and click on “Manage” next to the domain that you’d like to work with.
Select “Add Record” and choose MX. You’ll have to enter the following priorities and values for setting up MX records for Google Apps properly:
Priority / Value
1 / ASPMX.L.GOOGLE.COM
5 / ALT1.ASPMX.L.GOOGLE.COM
5 / ALT2.ASPMX.L.GOOGLE.COM
10 / ALT3.ASPMX.L.GOOGLE.COM
10 / ALT4.ASPMX.L.GOOGLE.COM