Reply to a message                             Manual page 153
Control + R

 Allows you to reply to a message.  You can reply to a message
 from the In box, or while you're reading a message.  This
 command brings up the message creation screen with the
 subject filled in with "RE: " followed by the subject from
 the message you're replying to.

 When you reply to a message, you can reply just to the person
 who sent the message, or to the sender and all the
 recipients:

                 +--------- Reply ----------+
                 |        Reply to:         |
                 |  Sender   All   Cancel   |
                 +--------------------------+