I have used the Act! Marketing Automation tool for quite a while now, and there were a lot of things that I liked about its e-mail campaign system. One of those things was the depth to which you can customize an action. If the email was opened you would send a different email. If it was not opened you would send a reminder. If the landing page was visited then you would do something else. If your team has never seen the Act! system, I would he happy to help with your research.
Overall, Act! was not great and was cumbersome. But there were some excellent tools in it.
I'm Excited to hear from your team.