Ironically, with the progression of technology (including the Internet, email, blogging, "tweeting," and text messaging), formal business letters have fallen as a method of correspondence. This is not to say that they are no longer used at all, however, and there is a proper format to follow in order to be completely professional and technically correct.
A business letter basically has 6 parts if it is not written on business letter-head, professional business paper with a logo and address already printed. The basic parts, and a few tips about each, are as follows:
- Sender's Address: this can be omitted if the letter is written on pre-printed letter-head which already contains an address.
- Date: date the letter is sent, month is fully spelled out.
- Inside Address: address of recipient, positioned in a way that when the letter is tri-folded, this address would show up in an envelope window pane (this is standard even if you are using solid envelopes and must re-print the address on the outside).
- Salutation: the greeting; use proper title and actual name of recipient if known; only use a "familiar" name if you know the recipient personally; follow the greeting with a colon.
- Body of Letter: the main thing to remember here is that the paragraphs do not need to be indented, only separated by a line of space.
- Closing: leave 4 lines between the closing remark ("Sincerely,") and your full typed name. Sign your name with a pen in the space.
If you are including anything in this formal letter, such as a resume or document of some sort, you will also include at the bottom of the letter (one line after the closing) a list of enclosures following the abbreviation Enc. for enclosure. You can either put the number of enclosures or list the titles if there are many.
The links below will provide more detailed explanation, as well as sample letters.