Signature and Designation of the person who writes the letter should be added in the right place meant for it. The letter should be signed by the person who writes that letter. Then only the letter will be treated lawfully and authentically. A letter without the signature of the person who writes the letters will be names as anonymous letter.
There should be adequate space between the complimentary closing and the name and the designation of the person who is writing the letter. The space should be enough to sign.
After the introduction of computer, business world has started to produce computer generated letters in bulk. Those computer generated letters will not get the signature and the designation of the person who writes those letters. But that statement will be there in those letters. This practice is adopted to save the time of signing the letters individually and of checking those letters for spelling correctness. In that case, the same letter can be sent to various persons (addressees) after changing the name and the address of the recipient.