Or if you want to keep the _messages_ in one central place, say, /etc/mymotd, you could add the /home/user/.profile like this:
/etc/mymotd
and the create /etc/mymotd
MYUSER=$(whoami)
if [ $MYUSER == "joe" ]; then
echo "Message for Joe"
elif [ $MYUSER == "john" ];
echo "Message for John"
else
echo "Message for everybody else, if any"
fi
Then chmod 755 /etc/mymotd. NOTE: I did not test this but it should not have any typos in it