Hello,
I have not used that plugin- I do not know.
If you are using Postman SMTP as suggested in the debugging steps, is it showing in the Postman logs that the email is being dispatched to the vendor?
If you deactivate all plugins except WC Vendors, Postman SMTP and WooCommerce…. is the email sent and delivered properly? The only way to know if another plugin is causing this issue is to deactivate all except WC Vendors and WooCommerce and then test. (In this case I advised that you leave Postman SMTP activated also since it will show in the logs if the email is being sent or not)
