These emails are sent on behalf of us by ICANN to ensure that your domain contact information is always up to date. The subject line is usually "Important Notice Regarding Your Domain Name(s)" We highly recommend following their guidance -- the more accurate your domain details, the easier it is to ensure you maintain ownership and control of the domain. The only trouble with these emails is that they're fairly generic for all domain registrars, meaning there isn't specific information describing how to update your contact information. Here are the steps!
From here you can update all contact information associated with the domain.