What gets populated at Dear ~Contact.FirstName~, when there is no name in the contact profile?
The default is “friend”
Look at this thread re: how to change default values:
https://integration.keap.com/t/set-default-value-for-custom-fields/76672/3
Jeff
Thank you
To continue in Jeff’s answer, you can enter [[ contact.first_name | default: "Friend" ]] in campaign emails and change that default value to whatever you want. You can generate a wide range of dynamic content yourself by going to Marketing > Dynamic Content.