I see a few challenges with the scenario:
1. The PBX is not an email recipient. It can relay a "canned" email through your smtp server, but there is no email receiving capability. This is the biggest hurdle to overcome.
2. Assuming for the moment that it could receive an email, there would be other or more issues to address. The email would have to be formatted in some fashion that the system could determine who to call and more importantly - what is the call handling at the system end? Is the system to act as a robo-caller with a canned message or once a call is placed does it ring an internal extension and whose?
So, the answer at the moment is no, it cannot in its current form support your desire. You could place a feature request and perhaps if they can figure out a way and if there is enough interest, they may incorporate.
There may be other systems that can read/parse thru and email and generate an action based on a phone number, I am just not aware of any, but others on the forum may have better info on the subject or methods that you might be able to employ to get close to your need using 3CX.
Good luck.