Comment 2 for bug 942566

I was able to reproduce the problem, and the short term solution is to make sure that the sender user in schooltool and at least one of the receiver schooltool users has an email address set up in their personal contact information. To set this up, please refer to this page in the schooltool book:

http://book.schooltool.org/contacts.html

and refer to the part where it explains how to access 'Add: Charles Brown as Contact' to get to the page where you can fill in an email address for a user. Again, be sure that the sender user and at least one of the recipient users has this email address set up.

In the meantime, we will update the New Intervention Message page to give an error message when the email addresses are missing.