Currently, if we ask for complements whereas there is no email input in form :

• Send mail checkbox is deselected but can be selected
• Following form fields are mail is disabled but can be enabled if the "send mail" checkbox is checked
• if select "send mail" it is not possible to validate dialog box as there is no email input

What we should do :
If there is no input email, we show a confirm box to user :

Le formulaire actuel ne contient pas de champ de type mail permettant de déterminer le destinataire de la notification. Le soumissionnaire ne sera pas averti de ce changement d'état. Souhaitez-vous continuer ?"