Since the default Magento 2 functionality is always a little bit limited, you can easily solve this problem with the aid of various third-party modules. For instance, Magento 2 emailing has a bunch of restrictions, but you can avoid them with modules, described below. In the following article, we collected Magento 2 email extensions that improve the way default emails are configured and delivered. You can find the appropriate marketing solutions here: Magento 2 Newsletter Extensions And Email Marketing Services. As for Magento 1 email modules, they are described in this post: The Best Magento Extensions For Custom And Improved Emails..