You can set up Web Messaging to either confirm or not confirm that your message has been sent.
Select Edit My Preferences from Personal Account Options.
On the Edit Preferences page, locate Confirm sent messages and select Yes or No.
Click the Save button.
If you select Yes, after you click the Send button, you will see a "Send Mail Status" page; if the message is sent successfully, the words "message delivered" and "success" are displayed.
If you select No, then after you click the Send button, you will return to whatever page you were on when you clicked Compose.