unanswer

UNANSWER  -  remove the A indicator from messages

Usage:  UNANSWER [message-sequence]
  Unless specified, the message-sequence is "current".

The UNANSWER command removes the A indicator from the header line of
  a message.  The A shows that you sent a REPLY or ANSWER.

Example:
    MM>headers 16
      A   16) 13-Feb abc4          Big party planned
    MM>unanswer 16
     16
    MM>headers 16
          16) 13-Feb abc4	   Big party planned

For more help type "help" and one of these topics:
  answer   reply   message-sequence   headers   message-tagging