Yahoo is rolling out new identification cards in its mail service, so you know exactly who is on your email chain.

Contact Cards will be available to desktop users, though the release is happening gradually throughout the U.S. — so you may not have the new technology just yet.

Those who do will be able to roll their mouse over an email address and a card featuring the person’s name, phone number, job title, and links to their social profiles will appear. Contact Cards aggregate information from your address book. In order to see Facebook profiles, users will need to connect to Facebook within their privacy settings. The cards are also actionable, so users can go to a contact’s Flickr page or call them directly from the card.

Contact Cards is powered by Xobni, an application software startup Yahoo acquired in 2013, and the new feature is very similar to products already on the market. Rapportive, for example, provides a Gmail plugin people can use to see LinkedIn profiles within their emails.

In addition to giving Yahoo Mail a competitive edge, Contact Cards also represent a move towards CEO Marissa Mayer’s goal of making Yahoo products ever more detailed and personalized.