I feel dumb. Lots of initial enumeration complete over a few days, but I’ve never worked the email angle. Can anyone start me with a good starting point? I don’t even know where to begin…
As always, enumeration is the key. Find out what services are running on the machine, how they are configured, how the are managed and installed. Do your research on every information you can find, if you do not know what it is or how it can be abused. Also, mail protocols are fairly easy to learn and understand so that might be the second step to take.
The rest on this box is just following your nose 