smtp server is an outgoing server, it will not receive any email(unless u set up pop or imap server). however, altho i think its a very normal function of any email client(i mean, you do not need to setup a receiving server when set up a outgoing server.), i m not using mail.app, so can't give you detailed instructions.
ok, i did a quick check, try
preference->account->outgoing server->add a server
In the General tab of the Mail preferences, you can set how often you want it to check for new mail. Just set it to 'manual' and it will only download new mail if you tell it to.