Quick Tip: Don't use your work email address for job searching. Use your personal email account, or set up a unique account to use just for your job hunt. Many free online email services exist, like Gmail and Yahoo mail, that you can use to set up a new email account exclusively for your job search.
Since your signature is likely to be difficult to read, type your name down a couple of lines so that your reader knows who is writing to them. Enclosures: (Below signature block) If you have included any further material _ a business card, a brochure, a price sheet, whatever _ list the number of items and describe each. Finally, proofread, proofread, and proofread again. While a friend might excuse even the worst spelling and grammar, a business letter is often your first (and maybe only) chance to make an impression _ it needs to be impeccable.