At the end you should sign off with "sincerely yours" or any other related salutation. If you are writing a letter of intent for graduate school then it would have a different content. First of all letter of intent would start with your name, address, contact number and email address. After you have mentioned the date, you should then add a salutation like "Dear Sir/Mam".
If you are writing a letter of intent for a business then there a few things you need to keep in mind. You may start your letter by mentioning your name, address, email address and contact number on the top left corner.