The Private Message feature is one of the strong points of the ProBoards software. There is total security between the person sending and the recipient(s); neither Administrators nor ProBoards staff can breach this. It is a great feature for conducting private chats that are off topic to the rest of the users.
You can access this by clicking on Messages on the main menu bar. From here, click Create Message and give a title to what you want to send, just like an email.
In the box marked recipients type in the Username(s) to receive your message. The system will recognise the precise spelling of the Username recognised within the forum. You can use the screen here exactly as you would use a screen in the public part of the forum, except that you cannot add attachments. You can still upload images embedded in the text like this one.
At the end of your message you click on Create Message to send and the recipient will see a little bubble beside Messages on their own menu bar, the number within showing how many are awaiting receipt. Click on Message to receive and you can Reply just like an email.