Why is proofreading a key component to validating the sincerity of your letter, email, or website?

Proofreading helps ensure that you are able to convey the intended message of your correspondence or content clearly. In a social exercise as malleable as communication, it is most important to use proper grammar and syntax, as it prevents occurrences of misinterpretation or ambiguity. Proofreading also aids in the improvement of others' perception of you - content that is either unclear or poorly written can give others the impression that one is lacking in communication skills as well as in other aspects; on the other hand, content that is clear and well-written gives off the impression that one is knowledgeable on the subject at hand.