Hello,
1 - Please clarify the context regarding the registration.
Joomla/HikaShop already send an email when the user is register ; so depending how you're performing the vendor registration, emails are already sent.
2 - There is an email for product approval in HikaMarket. Once the product approval is activated and the email is publish ; it will be sent to the administrator.
3 - In the backend, if you approve or decline the product ; you can check a box to notify the vendor.
You will find various email settings in HikaMarket.
In the first tab to see the emails and publish/unpublish them :
www.hikashop.com/support/documentation/1...ml#config_main_email
In the second tab for settings regarding what kind of notification you want to send :
www.hikashop.com/support/documentation/1...#config_market_email
Please note that if you have issues with emails you can see to activate the HikaShop plugin "email history".
HikaMarket is using HikaShop email system, which is using Joomla core function to send email (so based on the Joomla email settings).
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.