Mailchimp
You can connect your Gift Up! account to your Mailchimp account and every time you sell a gift card we will automatically add the purchaser's email address and name into the list you choose.
You will then see them in your list with the "source" being "Gift Up!"
Then you can set up some automation inside of Mailchimp to send the purchaser an email, perhaps inviting them to purchase another gift card a few months / a year later...