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 ImprovedEmails..
Fooman always does a brilliant job when it comes to Magento extensions, and modules for Magento 2 are not an exception. Therefore, we recommend you to install Fooman Email Attachments in order to improve the default functionality of your Magento 2 website. The Magento 2 email extension automatically attaches Invoice, Order, Shipping, or Credit Memo PDFs as well as Terms and Conditions to all your sales emails. The Magento 2 improved email module offers an absolutely free solution which will help you save a lot of time time.
It is also necessary to mention that Fooman Email Attachments offers a useful developer feature. If you write your own module or hire someone to do this you can easily hook into the email sending process run by this extension.
This Magento 2 email extension by Amasty offers a functionality that has been never available among default Magento features: SMTP Email Settings provides the ability to send reliable emails from a popular local hosting. Alternatively, you can rely on a custom Magento 2 SMTP server if you wish. Furthermore, you not only get a full control over Magento 2 SMTP settings, but get a perfect opportunity to test everything before sending any emails. Consequently, the Amasty SMTP Email Settings Magento 2 email extension offers the ability to check if your customers and partners receive all your messages.
Core features of Amasty SMTP Email Settings are:
Secure SMTP authentication and connection for Magento 2;
Pre-defined settings for various email service providers;
Reliable debugging for your your emails;
Flexible sending settings for Magento 2 emails.
For further information about this Magento 2 improved email module, follow this link:
With this Magento 2 improved email extension, you can easily resize product images and add them to your sales emails. The advantage of Product Thumbnail in Sales Emails is simple: customers receive a confirmation mail with a product image. In case of default Magento 2, the sales order email does not include the image of ordered items with the mail.