Question: what are the main roles and functions of correspondence?
Answer: Maintaining a Proper Relationship. It is not always possible for any business or organization to reach to any person in particular. ... 
Serves as Evidence. Any written form of communication serves as evidence. ... 
Create and Maintain Goodwill. ... 
Inexpensive and Convenient. ... 
Formal Communication. ... 
Helps in the Expansion of Business.