I agree with everything above except for documentation. I'm getting ready to roll out courier-imap for a medium scale webmail application and while I'm very happy with the product so far, I think some of the documentation was a bit lacking (i.e. "large server farm"), which is why I wrote the HOWTO that I posted earlier on this list. I mean, what good is an awesome email server like courier-imap if admins give up on it because they can't configure it? I'm hoping as the HOWTO is refined it will help admins see courier as a viable option. It would be a shame to see all of Sam's hard work go to waste because of lack of comprehensive documentation.