Hard to say without knowing any details.
The answer could be from "stop sending yourself copies" to "check your
Google account settings";
http://www.howto-outlook.com/howto/accountsettings.htm
Without any details, it would of course just be guessing if you are actually
using a Google account.
Include at least;
-your version of Outlook (Help-> About)
-type of mail account (POP3, IMAP, Exchange, HTTP, Outlook Connector,
Exchange, other...?)
-any errors in their exact wording as they are presented to you.
