Is it set to filter on anything?
Is the email set to send on post.
My guess is that the recordset is set to filter on URL variable which exists when the page opens, but is not passed as part of the form action, so when the form posts, the recordset is now empty.
It would be helpful to have the entire page to see the code in context instead of the code snippets, the snippets never tell the whole story.
I altered the file slightly -- added a hidden form element that should have passed the teacherEmail to the form info (line 370), changed the assignment of the mailto address to that element. Still no joy. . .
I'm sure it's something simple -- be gentle!!