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".
The long and short of the story, is that the court, after scrutinizing not only the Memorandum, but also the wordings of the press releases and other documents that Getty Oil and Pennzoil had issued over the course of their dealings, found Getty Oil to be "in breach" of the Memorandum of Agreement _ the document the parties had viewed as a letter of intent. Thus, a document (the letter of intent) that the parties had started out viewing as non_binding and unenforceable, had changed from being that, to being a final agreement! Pennzoil, on the other hand, ended up with บǒ billion (later settled for ū billion) from Texaco for interfering in its deal with Getty Oil.