I discovered that it is possible to send a totally empty form via CF7. It happens as long as none of the fields is a required one. But that actually shouldn't work, should it?
Look, I have a form consisting of two fields and a submit button. The sender may choose whether to fill in the first one (e-mail field) or the second one (phone no. field). So I cannot make any of these required. But now it can get send even when both fields are empty.
How to solve this problem?