Put these two lines in your remotes (Alt-R):
on *:TEXT:*:?: $+(.timerquery.,$nick) 1 30 close -m $nick
on *:INPUT:?: $+(.timerquery.,$active) 1 30 close -m $active
NOTE: You will only have 30 seconds to respond to anyone who msgs you before you miss the message entirely.
DALnet: #HelpDesk and #m[color:#FF0000]IR[color:#EEEE00]C