Try to find out the name of the Hiring Manager so you can customize the greeting/salutation of your cover letter. If you are unable to do so, use “Dear Hiring Manager” or “(Name of Department) Manager” or even “(Name of Job Opening) Search Team”. Avoid using “Dear Sir or Madame”, or worse “Dear,”.
WHY: Customizing the greeting signals to the hiring manager/team that you took the time to do some research. “Dear Sir or Madame” is considered dated in some circles.