I do remember using WorkMarket a long time ago and experiencing the bizarreness of their emails as they were one of the very few AMP users.
They'd send out emails about work opportunities and leveraged AMP to be able to go back into the email and tell you if it's still available to apply for or not in realtime, so you wouldn't have to click through and be disappointed it was already taken.
I'm surprised more people don't use images for this kind of thing. You could put an image with a green checkmark next to every live job posting, and change it to a red X once the job is no longer available. I worked for a publisher of email newsletters and we ran a bunch of tests into the caching behavior of email clients to see how viable this kind of thing would be. Turns out it's pretty easy to implement and works just about everywhere.
They'd send out emails about work opportunities and leveraged AMP to be able to go back into the email and tell you if it's still available to apply for or not in realtime, so you wouldn't have to click through and be disappointed it was already taken.