In the 'User profile for new users' form is it possible to remove the requirement for an e-mail address? I want to register students who do not (or may not) have an e-mail address. At present it is not possible to register them because of the requirement to provide an e-mail address.
Always remember to search moodle.org's forums before asking your question, as it's very likely that the question has been answered before. In this particular case, search for "register with no email address", or similar keywords/phrases.