Mail is related to Delivery. Delivery is derived from Deliver. Deliver is related to Guy. Guy is related to Reference. 
Encouraging is related to Helpful. Helpful is related to Cooperative. Cooperative is the opposite of Competitive. Competitive is related to Advantage. 
Mail <--RelatedTo--> Delivery --DerivedFrom--> Deliver <--RelatedTo--> Guy <--RelatedTo--> Reference 
Encouraging <--RelatedTo--> Helpful <--RelatedTo--> Cooperative <--Antonym--> Competitive <--RelatedTo--> Advantage 