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A letter is a written message containing information from one party to another. The role of letters in communication has changed significantly since the nineteenth century. Historically, letters (in paper form) were the only reliable means of communication between two people in different locations.
As communication technology has diversified, posted letters have become less important as a routine form of communication. For example, the development of the telegraph shortened the time taken to send a letter by transferring the letter as an electrical signal between distant points. At the telegraph office closest to the destination of the letter, the signal was transferred back into a hardcopy format and sent as a normal mail to the person's home. This allowed the normal speed of communication to be drastically shortened for large distances. The facsimile (fax) machine took this one step further: an entire letter could be completely transferred electrically from the sender's house to the receiver's house by means of the telephone network as an image. Today, the internet by means of email plays a large part in written communications.
Historically, letters exist from the time of ancient India, ancient Egypt and Sumer, through Rome, Greece and China, up to the present day. Letters make up several of the books of the Bible. Archives of correspondence, whether for personal, diplomatic, or business reasons, serve as primary sources for historians.
The study of letter writing 
Due to the timelessness and universality of letter writing, there is a wealth of letters and instructional materials (for example, manuals, as in the medieval ars dictaminis) on letter writing throughout history. The study of letter writing usually involves both the study of rhetoric and grammar.
Letters are still used, particularly by law firms and businesses, for official (public) notifications, sometimes advertising. This is because of three main advantages:
- No special device needed - almost everybody has a residence or other place at which he or she can receive mail. A mailbox is all that the intended recipient needs - unlike e-mail or phone calls, where the intended recipient needs access to a computer and an e-mail account or a telephone respectively.
- "Catch-all" advertising- unlike e-mails, where the recipient needs an individual e-mail address to receive messages, individuals are not necessarily chosen, by rather can widely cover many or all addresses in a given locality.
- Physical record - important messages that need to be retained (e.g. invoices; government notification such as tax or immigration) can be kept relatively easily and securely.
The letter-delivering process 
Here is how a letter gets from the sender to the recipient:
- Sender writes letter and places it in an envelope on which the recipient's address is written in the centre front of the envelope. Sender ensures that the recipient's address includes the Zip or Postal (if applicable) code and often he includes his return address on the envelope.
- Sender buys a postage stamp and attaches it to the front of the envelope on the top right corner on the front of the envelope.
- Sender puts the letter in a postbox.
- The national postal service for the sender's country (e.g., the Royal Mail, UK; US Postal Service, US; Australia Post in Australia; or Canada Post in Canada) empties the postbox and takes all the contents to the regional sorting office.
- The sorting office then sorts each letter by address and postcode and delivers the letters destined for a particular area to that area's post office. Letters addressed to a different region are sent to that region's sorting office, to be sorted further.
- The local post office dispatches the letters to their delivery personnel who deliver them to the appropriate addresses.
Letter layout 
United Kingdom, Canada, and Australia 
The following is a common way to set out a letter:
|Sender's address here|
|24 Lambert Street|
|Formal: 18 May 2013 Informal: May 18|
|Recipient's name and address here|
|Mr Joseph Bloggs|
|25 Lambkin Street|
|Formal: Dear Sir or Madam, Acquaintance: Dear Mr Johnson, Informal: Dear Boris,|
|Formal: Yours faithfully, Acquaintance: Yours sincerely, Informal: Best wishes,|
|Formal: Sender's Occupation and Enclosures Informal: Nothing (optional: P.S. / Post Scriptum = Afterthought)|
United States 
The following is the modified block format for a business letter, common in the United States:
May 18, 2013 Your Address
Date Mr Jack Brough
25 First Street
Anytown, VA 10005 Dear Mr. Brough: This is an example of a modified block letter. The difference between it and a full block letter style is that the date begins at the center point of the page; therefore, if a letter has a 6 inch line of type, the date begins approximately over 3 inches from the left margin. The closing block also begins half-way across the page. The complimentary close and the keyed signature (first and last name of the writer) begin at the same point as the date - approximately 3 inches from the left margin. Sincerely, Robert Hayward Sales Representative
There are a number of different types of letter to serve different social purposes.
See also 
|Look up letter in Wiktionary, the free dictionary.|
|Wikimedia Commons has media related to: Letters (written messages)|
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