Eudora has very good email sorting ability. You can route messages to different inboxes and outboxes based on sender, recipient, subject and other things.

For awhile, I had it all organized: specific people were associated with specific projects, so I could assign sets of people to specific inboxes and outboxes and find all the mail for one client in one place.

However, recently I've gotten other projects involving the same people. So now those people are not exclusively associated with one client. I'm not sure what to do. I can't just sort mail by person, because then mail for an individual client will be dispersed among multiple mailboxes. I really need some kind of compound rule system, and I'm not sure Eudora has it.

I should have seen this coming. In the world of small business, it's the same set of people working with each other over and over again. Unfortunately, that is in tension with the capabilities of my favorite e-mail application.