ircII help: set auto_unmark_away

Usage: SET AUTO_UNMARK_AWAY [ON|OFF|TOGGLE]
  When ON, you will automatically be unmarked as being away (as
  if you had issued an AWAY with no arguments) if you send a
  message to a channel or send a private message.  When OFF, your
  away status will remain unchanged until you issue the AWAY
  command with no arguments.