The Magento 2 Transport Builder, responsible for preparing a mail message, wraps the mail component of the Zend Framework. Unfortunatly it is missing a method to add attachments. I submitted a Pull Request to Magento 2 to fix the issue but for now we need a work-a-round in our project. First we extend the Magento 2 Transport Builder like this:
A few weeks back we released a Prophiler PSR-7 middleware which we created during a hack session on Adroit, our little, clever ADR middleware implementation. I`d like to show you how to integrate the Prophiler middleware in a zend-expressive application. As it turns out this is super simple.