src/Message.php
public function template($template = 'email.volt')
    {
        $this->viewPath = $template;

        //if we have params thats means we are using a template
        if (is_array($this->params)) {
            $content = $this->getManager()->setRenderView($this->viewPath, $this->params);
        }

        $this->getMessage()->setBody($content, self::CONTENT_TYPE_HTML);

        return $this;
    }
public function template($template = 'email.volt')
    {
        $this->viewPath = $template;

        //if we have params thats means we are using a template
        if (is_array($this->params)) {
            $content = $this->getManager()->setRenderView($this->viewPath, $this->params);
        }

        $this->getMessage()->setBody($content, self::CONTENT_TYPE_HTML);

        return $this;
    }
view relative to the folder viewsDir (REQUIRED)

@param string $template

@return $this