Perhaps you are emailing a recruiter at the PR agency you want to work for.
(these suggestions are coming directly from Adi, the head hunter at Edelman)
Make it easy for them to help you.
You will be more successful if you are following your passion.
Tell what you want. Never say that you don’t know.
Don’t just ask to have your résumé reviewed. What do you want? What do you have to offer besides a résumé?