The Messages tool allows you to reply to a message sent to you by another member of the course.
Select Messages.
In the target Sakai site, select the Messages tool from the Tool Menu.
Go to Received folder.
Select the Received folder to view a list of your received messages.
Open the message.
Select the subject of the message you would like to view.
Choose Reply or Reply to all.
Select Reply to reply to the author of the original message. (Or select Reply to all to reply to all site members included on the original message.)
Compose the message and send.
Compose the message and select Send. For instructions on composing a message, view the article How do I send a message?