Associate email with a potential or project.

Associate email with a potential or project.

I have a pivotal requirement to associate emails from various suppliers (contacts) with different potentials or projects, on an email by email basis as they come in.

This question appears to have been raised before but I cannot find a definitive yes "it can be done".

Could anyone please tell me, yes or no. 

If the later I can stop wasting time and look at alternative crm systems. I would love not to have to do this. Thanks in advance.