you can create a job for the scheduler.

What I have done is developed a custom schedule item to send an email.

There are however a few problems with this way of working:

1. there seems to be a bug in the dnn scheduler which runs schedule items more often than configured (see my post elsewhere)

2. you cannot set the time of a daily schedule. The only way to get this to work is to update the schedule item at the time you want it to run daily. So set your alarm clock if you want it to run in the middle of the night!!!

good luck.

if you need code examples look at the scheduler documentation or I can send you a sample.