Hello Matthew,
Not only am I an excellent creative wordsmith, I am a native English native speaker with first rate skills in all aspects of English including grammar, vocabulary, sentence formation and sentence correction (proficient in USA/AUS/UK/CAN English).
So proofreading your letter is a natural fit for my abilities - so in hiring me, you will be hiring the best - why settle for anyone less?
I look forward to your positive response by return.
Kind regards,
Nick