I think most email clients only block images that are being loaded from a remote server,
If you include or embed the images then it shouldn't block them.
The reason email clients started blocking remote images is because it was a way of determining what email addresses opened an email and when they opened the email. Often times this was used to spam. A spammer would send out emails to auto generated email addresses a@example.com, b@example.com, c@example.com
then they embed an image tag with a unique query string attached to it
<img src="http://example.com/images/image.jpg?id=a@example.com" >
Then they look at their server logs to see what query strings loaded that image and then they can tell which email addresses have actual people opening the emails at.
If you embed the image in the email then you can't track it and your email client won't block it. However embedding images has the effect of making the email size much larger.
You can look at some Image to CSS converters.
I am not sure what Adobe is doing but it could be they have white-listed some of their servers with some email providers. I know Thunderbird blocks images from them.
