Navigate to connect > messages and find a message that you would like to reply to from your Inbox or Sent folder.
Click the row to unnest the message and click the button labeled Reply.
A reply field will appear below the original message where you can enter your response to the message, select if this message is addressing an Engagement Opportunity, and/or add attachments to the message.
Note: The reply feature functions as a reply all. You cannot change the recipients of a message when replying.
The reply will appear in your Sent folder, collapsed with the original message.