Whether you're submitting a resume cold or responding to a job posting, always include a cover letter. Yes, they're tedious to write, but a solid cover letter can make the difference between getting the job and getting nowhere.
Address the Recruiter: Start your letter with the date. Skip two lines and write the recruiter's full name, preceded by Mr. or Ms. Then, list the recruiter's title and the company name and address. If you don't know the recruiter's name, simply list the company name and address.