Your request letter should use the proper business letter format, as it is likely a formal request. This applies whether you're sending an email or a hard copy letter. Become familiar with the following format and be sure to use it when writing your letter.
Place your name, title, and address on the top left of the paper. Place the date below this. Put the person's name, title, and address below this. Address the person appropriately. Start with "Dear Mr." or "Dear Mrs." Have 1-inch margins around the paper and use single spacing. Don't indent, just use a double space in between paragraphs. Use an easy-to-read font such as Times New Roman or Arial, in 12-point font. End with "Sincerely," then leave 4 lines so you can manually sign your name. Below this, type your name and title.