How do I get rid of the link that appears at the bottom of registration email?

Hi,

When a visitor to our site registers, they receive an email with their username and password, and a link to the dashboard. How do I either get rid of that link completely, or change it so it goes to our home page. Nobody other than Admin should be looking at the Dashboard. I don't know why that link is appearing on the email, but it's gotta go.

Thanks,

Sherry