I am almost looking for the same solution. I would like a winpopup notification when email arrives at the server.
This is what i got so far:
tail -f /var/log/qmail/current | grep -B 1 "to local" | smbclient -M pc > /dev/null 2>&1
It doesn't work. At least the tail and grep work, however smbclient -M stops and asks for a control-d to stop and send the message.
I saw somewhere the > /dev... stuff, and tried it, but no go.
I was sure I saw something like this posted a couple years ago, and sure it must be possible to do somwhow. A person could backgroud it with "&" and turn it into a task.
This may work for your idea for maybe watching the dhcp logs as well. We just got to find that old post, or if someone out there remembers.
Later.