Hi,
We have already developed very close to this and this is operational some clients with a version of mysql higher than 5.0.25.
We have developed a mysql function that can be called from any SQL statement and that can send mail to a list of e-mails recipients defined as input parameter.
This can be called from a trigger as you request it, or from any sql statement you write anywhere.
Please advise if this is what you're looking for
Regards,