The lawyers add that: "This is the legal problem with a Letter of Intent _ you can't legally state you agree to something and then state that you don't in the same document." Famous Case of a Letter of Intent Gone Bad: Court Case of GETTY OIL vs. PENNZOIL
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".