By "code error notifications", I'm assuming you mean the emails you get when there's a 500 exception.
Three settings control this feature.
SERVER_EMAIL – who the email is shown as coming "from". Some SMTP servers will reject any email not coming from a known account. Try setting this to your Dreamhost accounts's email address.
ADMINS – a tuple containing of list of who to email when problems occur. Make sure this is set up with your email account listed:
ADMINS = (('Jack Shedd', 'jack@example.com'),)
DEBUG - Must be set to
False