What is Reciprocity?

“The reciprocity function enables you to automatically send Mishloach Manot to people that are sending to you. This is a great tool to ensure that you don’t inadvertently miss someone and that everyone that sends to you, gets a Mishloach Manot  from you in return. Please DO NOT rely on this alone—if everyone just chooses reciprocity, and doesn’t select any recipients, no one will get any Mishloach Manot!”