I have had some success with this option and have the "Interval" set to 4 hours.  I understand that this option prevents additional copies of the message from going out for a given amount of time. The first use of the AutoResponder seemed to work reasonably well.
I have a few e-mail address of which I can use to test and a few students did get a correct response.

It is a week later and now I want to use it again for the same group.  I went in and changed the message and changed Subject from QUIZHINT to QUIZHINT-42 and now it does not seem to work at all.

Is there some other reset needed?
What might I be doing wrong?


Ok, editing my own message here (-:
I just created a new AutoResponder message and it seems to work properly.  Apparently one cannot reuse an existing message.