Hello,
Thank you for choosing our component.
To receive email notification need configure at first Joomla mail settings ( test with Mass Mail Users)
docs.joomla.org/Help36:Users_Mass_Mail_Users
+ add email in VehicleManager : Settings - Email and Notification Settings - Rent Request Options
follow attached image.
If you would like any further information, please do not hesitate to contact us too.
Best Wishes,
OrdaSoft team