I have done this for another saas customer (not CA PPM) that uses Outlook 2010 which might work.
What we did was hosted the images that we needed for the emails on a site within the company and set the image tags to the local url for a given image.
This customer's exchange server was configure to trust the images in emails that originated from the intranet.
So when a user opened the email, they didn't need to do the click to download images.
I haven't tried this with PPM and I don't believe either the gel:email or jelly:email tags post process the message text.
V/r,
Gene