Messages (also known as personal messages or PMs for short) were a feature on Total Jerkface. Private messages were used as a way to communicate with other members of Total Jerkface privately, as they could not be seen by others, as suggested by their name. When a user is logged in, they could see how many new messages they had in the top-right corner of the Home Page, in between their username and the logout feature.
The messages section displayed the title of the message, the status (unread or read), who sent the message, and the date it was sent. When inside a message, the user who received the message could reply by pressing the reply button down the bottom.
There was a quite common bug present for some users that would say they have messages (the number will vary), though their inbox was in fact empty. This would be stuck here for very long intervals of time, if not forever, and would always say they had that many messages. Jason did say that this would be fixed with the "site architecture" update, which will presumably include new forums and a new message system. This glitch later was fixed with no change to site architecture.
Soon afterwards, due to very frequent glitches, and using a lot of server bandwidth, the message system was shut down. It is unknown when (or if) it will be replaced. When the messaging system got removed, the icon for it and the number of messages was removed too.