A person can send a personal message to someone on Facebook by logging in to his Facebook account and clicking the "Messages" button from the menu on the left. Clicking the "New Message" button and filling out the form to send a message completes the process. A sender may include up to 250 people in a single message.
The first step to sending a message on Facebook is typing the name of the intended recipient in the "To" field. Names of the sender's friends typically appear in a drop down menu, and the sender can then select the friend he wants to receive the message. The next step is to type the message in the main message box and click the send button. Alternatively, a Facebook user can go to the profile page of the person he wants to contact and click the "Message" button located at the top of the page.
If the intended recipient is a Facebook friend of the sender, the message should be delivered to his Facebook inbox. If a Facebook user messages someone who is not his friend on Facebook, but the message might bypass the inbox and be delivered to the "Other" folder. For a fee, Facebook ensures the message is delivered to the recipient's inbox. If the user receiving the message is logged into Facebook chat or messenger, the message pops up immediately in a chat box. Facebook marks messages as "seen," so senders know their messages were received.