Yes. Follow these steps:
1. Sign into your account.
2. Go to eCards > Sent Cards in the navigation.
3. Click on the thumbnail of the card you want to view/resend. (You'll know which cards have not been viewed by the gray 'closed envelope' icon next to it.)
4. If a sent card has not been viewed by at least 1 recipient, in the Options drop-down list you'll see a selection for "Copy Card - Add All Who Did NOT Pick Up". Select this option and you'll have created a copy of the original card that you can edit, that's pre-addressed to every original recipient that did not pick up your card. Edit the card as you wish and send it!