You can send direct messages in Twitter to @anyone who is following you on Twitter. Once you hit the Send button, the DM will instantly appear in the recipient’s email inbox and, depending on the settings, as a text SMS on their mobile phone.
At first glance, the DM feature in Twitter may resemble web email but there are two important differences between email and Twitter DMs:
#1. If you send a DM to @xyz who then deletes that message from his or her inbox, the DM will also disappear from your own “Sent Items” list in Twitter. In email, neither the sender nor the recipient has such control over each other’s mailbox.
#2. In an email program, you can always send a message to your own email address but Twitter’s web site would only allow you send DMs to your followers – you cannot send direct messages to yourself.
I can’t think of any reason why you may want to send DMs to your own @Twitter account but if ever want to do that, web-based Private Tweet might come handy.
Just sign-in with your Twitter account (it uses OAuth so you don’t have to share your account credentials) and all you’ll see is a big compose box – anything you write here will instantly get saved to your Twitter account. And since this is a self-addressed direct message a copy of the DMS will get saved both in the Inbox and Outbox of your Twitter account.
Also see: Send DMs to Multiple Twitter Users