GiftWorks stores letter templates in .rtf (rich text format), which when you email, can become the body of the email. You can enter standard http://... and https://... references as well as standard name-@-domain addresses and they will be sent out as text
If you prefer to have a hidden link where a key word is underlined and often colored to denote that clicking "HERE" will take you to that location, open a Word document and create your text to be the link there, save as .rtf format. Then use Word's "insert weblink" tool to record the underlying web address. Then copy it and paste that text into your GiftWorks template. GiftWorks has an Insert Hyperlink option on the toolbar when adding or editing a letter.
If the recipients computer is set to receive only plain text format, they wont be able to click on the link to have any action executed Certain email programs do not support links conveyed in text documents. Instruct recipients that if the links aren't active, they can copy and paste the link into their browser, or the email address into the email TO: line