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".
A famous example often cited by legal scholars, was a case involving the Getty Oil and Pennzoil in very early 1984. The parties had signed a "Memorandum of Agreement" _ viewed by the parties at the time as a Letter of Intent _ for a complex investment and stock transaction, whereby Pennzoil would purchase Getty Oil stock, and set forth general terms of the investment that had been reached in conversations, and also stipulated that the Memorandum was subject to the approval of the Board of Getty Oil. The Board of Getty Oil sooner approved the transaction and both parties announced on January 4, 1984 in a press release, an "agreement in principle" to the terms of the Memorandum. The final agreements for the merging of Texaco and Getty Oil were signed by the parties on January 6 _ 8.