Using Merge Tags
Merge tags allow you to dynamically populate your contacts info into a message. This is especially helpful when sending bulk messages or creating an AutoSeries. Rather than saying "hello Sir or Madam" you can Say, "Hi Dan,"
On any message screen, look for the drop down that will show you available merge tags you can use
Recipient Fields are populated by the contact you're sending to where as Site & Sender fields are your information.
eg. a common greeting would be Hi [recipient first_name]