"mailman send an email to ... when program this program/simulation is done"

mm.zsh

#!/usr/bin/env zsh
TO=root@localhost #EMAIL address of the recipient
HOST=127.0.0.1 #HOSTNAME with SSMTP service
main()
{
    START=$(date +%s)
    STARTT="$(date)"
    OUT="$(mktemp mm.XXXXXXXXXX)"
    echo "##[mm]: launched in folder $(pwd) with pid $$" > $OUT
    echo "##[mm] received output:" >> $OUT
    if [ "$1" = "-" ]
    then 
        cat - &>> $OUT
    else 
        $@ &>> $OUT 
    fi
    SUB="[mm]: '$@' by $(whoami)@$(hostname) at $STARTT"
    SEDEXP='1i ##[mm]: "'$@'" ran for '$(($(date +%s)-$START))'s'
    sed -i "$SEDEXP" $OUT
    tail --bytes 1000000 $OUT | ssh $HOST "mail -s \"$SUB\" $TO"
    rm -f $OUT
}
if [ $# -eq 0 ]
then
    echo "mm: to what do I owe the extreme pleasure of this visit?"
else
    main "$@" &
    disown
fi
exit 0