I have set up SSMTP and confirmed it working correctly: emails can be sent manually and through zm. The problem is with the attached images.
Essentially I am experiencing the same problem as OP from This Post from 1.30.
All images sent via email are getting corrupt somewhere in the sending process and look like this:

I verified that the image is not corrupt before attaching and sending..
Just at an brick wall now. Anyone have any advice?