[Dovecot] Using MySQL to store email?

[Marc Perkel]

Here's an example of what I would do with a MySQL backend.

I have an inbox where I get email for a wide variety of subjects. One of 
those classifications are customers. So I would create a customers 
folder and have a rule that if an incoming email from address match any 
email address in my customers folder then the mail would be delivered 
there. That way if I get a new customer then all I have to do is drag 
the first message into the customers folder and all other mail from that 
person would go into that folder.

To do this with MySQL would be trivial. To do it without a database 
isn't possible.