From the Google forum:
How do you delete a Gmail account?
If you'd like to close or delete your Gmail account
then you can do so by following these instructions:
Visit this page after signing into the account you would like to delete Gmail
You will have two options:
a) "Remove Gmail permanently": this removes the Gmail service but keeps any other Google services (Calendar, Drive, Blogger ...). All your emails and contacts are deleted permanently. You need to specify a non-Gmail email address as your new login for other Google services that you log into. If you want to delete or close your Gmail account but still use other Google services like Google Drive, then this would be the option for you.
b) "Close account and delete all services and info associated with it": this removes the whole Google account including all services that you used with this login (Youtube, Picasa, Blogger ...). This step is irreversible and you can never use the same username again. If you want to delete or close your Gmail account as well as any associated services with your Google account then you would choose this step.
If you are a Google Apps user (aka your email address is through Google but does not end in @gmail.com
), then you will need to contact your organization's Google Apps administrator who will follow the procedure here for removing your address from the Google app domain
We're sad to see you go! If you have recommendations on what would make the product better, you can submit it by clicking the gear icon in the upper right hand corner of Gmail and selecting "Send feedback"