If I were you I'd check with this 'contact' and find out if he/she really did send them out!?
Even so, if you receive any more e-cards, and are uncertain as to the senders credentials. You and everyone else, should get into the habit of never clicking on links contained within e-card notification email's. Instead, go directly to the website of the card company, find the card pick-up page within that site and enter the ID code included in the email you were sent. (If the message is a fake, the worst that will happen is that you won't get a card)