I have exactly the same problem, but Im not sure how Im supposed to run the command by hand.
The command seems to be
"/usr/bin/printf “%b” “***** Nagios 2.8 ***\n\nNotification Type: $NOTIFICATIONTYPE$\n\nService: $SERVICEDESC$\nHost: $HOSTALIAS$\nAddress: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$SERVICEOUTPUT$" | /usr/bin/mail -s " $NOTIFICATIONTYPE$ alert - $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **” $CONTACTEMAIL$".
Running that by hand on commandline surely will result in nothing, since none of the variables are defined in my environment.