How to send image attachment with email template in magento 2

For Attach image in email template, you need to override TransportBuilder Class from Magento\Framework\Mail\Template\TransportBuilder

For Send Email Magento 2 without image attachment refer link,  Send Mail from Custom module Magento 2

For Override TransportBuilder.php file in Magento 2, you need to create di.xml file.
Using di.xml file you can override any PHP class in Magento 2.

Create di.xml in your module,

Create TransportBuilder.php file at below location,


Create helper file to send image attachment in mail template,