product contact email doesn't work

-- HikaShop version -- : 4.2.2
-- HikaMarket version -- : 3.0.3
-- Joomla version -- : 3.9.1
-- PHP version -- : 5.6
-- Browser(s) name and version -- : firefox
-- Error-message(debug-mod must be tuned on) -- : no error message

Hello,

I'm using hikamarket and hikashop together to run a multi store for auto parts. Vendors are people who are selling an auto part. When shopping in the front end of hikashop and viewing a product you can click a button: "Contact us for more information". This form submits but the email never arrives to the vendor's email inbox.