PREUN
/bin/sh
if [ $1 -eq 0 ]; then update-alternatives --remove mutt /usr/bin/mutt-normal fi
POSTIN
/bin/sh
update-alternatives --install /usr/bin/mutt mutt /usr/bin/mutt-normal 10
Triggers
mutt < 1:1.5
/bin/sh
update-alternatives --install /usr/bin/mutt mutt /usr/bin/mutt-normal 10