When sending html mails created with com_mails it is possible to include images.

The function convertRelativeToAbsoluteUrls ensures that the images have absolute references so that they will be loaded in the email.

However if the image has been added to the email using the media manager it will include loading="lazy" and data-path=

This is not supported by many email clients so as well as converting to relative urls we should also be using the function cleanImageURL to ensure greater compatibility

Reference

https://www.caniemail.com/search/?s=loading