app/mailers/spree/supplier_mailer.rb
module Spree
class SupplierMailer < Spree::BaseMailer
default from: Spree::Store.current.mail_from_address
def welcome(supplier_id)
@supplier = Supplier.find supplier_id
mail to: @supplier.email, subject: Spree.t('supplier_mailer.welcome.subject')
end
end
end