When you login this BigAnt messenger, you will see the main panel, locate people/group you want to contact in structure list, double click the target contact to open the chat window. Just type your message, and click enter to send.

Tip: Press CTRL + Enter to start a new line when typing a list in your chat window

Message receipt

A message receipt helps to know if your message is read when you are looking for a reply from the contact you are messaging. There will be an unread tag beside the message you sent, and it will disappear when the contact opens your message.