[ADMIN] how to trigger an email?

[seb]

Hi all,

I use a database to store dynamically logfiles 
for network management purpose.

If something goes wrong 
( an entry shows up in a log table with a specific pattern )
I would like to be warned immediately via email.

Does anyone has a short solution for that,
with a trigger or a rule?

Thanks in advance,
                                Sebastien.