Customer can't find the e-card I sent her.

[NAHs]

Can I delete an e-gift card? I e-mailed a card to a customer, she said it did not show up in her email, I sent another and she still can't find it. What would the subject be on the email? Can I delete the old one I sent before I try sending one to a different email address. She said it is not in her junk.