This article shares a best practice for including a URL in a template that you are sending that will be sent to the donor via email. This process does not work for printed letters.
If you would like to direct your contacts to a specific URL in the email you are sending, you can do this easily by typing out a complete URL in the template of your email address.
For instance, if you want to point a donor back to your website or another landing spot, simply adding in the "http://" prior to the URL will allow the recipients email provider to properly convert this text to a clickable URL.
Please note: This feature is not guaranteed to work, as it relies upon the donor's email provider to properly convert this text to a clickable link.