Go here to login with your email address and password:
http://www.homeexchange.com/login.php

If you forgot your password, you can retrieve it via email from that same page.

Once you Login to the site with your Username and Password and you will end up at the "Your HomeExchange.com Account" screen.

From there you want to set your email notification details, so click on EMAIL ME WHEN NEW LISTINGS COME IN

On the resulting page you will be able to edit your new listing notification details:

You can add or delete separate COUNTRIES or US STATES/AUSTRALIAN STATES/CANADIAN PROVINCES by scrolling the list up and down and clicking on the country you want to select or delete (if you clicked on a currently highlighted one). Then at the bottom of the screen click "Notify Me".

You can add or delete multiple COUNTRIES or US STATES/AUSTRALIAN STATES/CANADIAN PROVINCES by holding down the "Ctrl" key (PC) or Command key (Mac) while clicking on up to twelve new locations (clicking on the currently highlighted ones to remove them) from the scrolled down list. Then at the bottom of the screen click "Notify Me".

You can delete ALL the COUNTRIES or US STATES/AUSTRALIAN STATES/CANADIAN PROVINCES by clicking "Stop Notifications".

Finally you can click in each of the boxes for New and Edited Home Exchange or Rental listings to detail which listing types you want email notifications for.