Twitter is a popular microblogging service designed to keep your friends and followers informed of your activities from day to day. Popular with users for its simplicity and ease of use, Twitter limits the number of characters in a "tweet" to 140 -- this is the maximum length of an SMS message. In addition to tweets, Twitter also supports a "Direct Message" feature that you can use to send private messages to another Twitter user. Like a standard tweet, the 140-character limit applies to direct messages. You can always exceed that limit, though, sending a longer message and forcing Twitter to split it into two or more parts.
Click the "Messages" tab at the top of your Twitter account to open the Messages window.
Click the "New Message" button to send a direct message.
Type the username of the follower to whom you want to send the message in the "To" box at the top of the New Message dialogue.
Type your message in the "New Message" dialogue. If you exceed 140 characters, your message will be split and sent to your follower as two or more messages.
Click "Send" to send your message.
You can send direct messages only to your followers.
Make sure your Internet or wireless signal is strong before sending a long direct message. If your message is sent in two parts and you lose your carrier signal during the transmission, Twitter may post the second half of your message directly to your public tweets.