For uploaded or mailed cover letters, you do not need to include as much information as you would in an email message, because the heading of your cover letter includes your contact information. For a paper cover letter, use a formal business_style letter format which includes a heading, salutation, the body of the letter, closing, and your signature. Review these guidelines for what to include in your letter.
I can’t tell you how many truly awful letters I’ve had to read in my life. As a former administrative assistant, I was responsible for all the unsolicited submissions to a major New York museum. Artists and collectors all over the country (and abroad) wrote to have their work considered for display or acquisition, and to be honest the decision frequently rested more on the quality of their cover letter than on their work _ which, romantic dreams aside, rarely if ever sells itself.