I have a Debian server running Postfix and Courier for IMAP. Currently, my mail queue is /Maildir. The problem is that we've added over 50 users to the server (company acquisition) since putting in this machine. Users are complaining that the machine is slow. One suggestion from someone was setting up MySQL to hold the email instead of putting the email in /Maildir. I've been trying to find articles to set this up but it looks like the only articles I find talk about setting up a users table in MySQL, not putting email in the database itself. I'd prefer to go to Exchange, but the cost of CALs for these users (143 total including the 50) is more money than my company wants to spend. I'm not worried about the server hardware itself. That is one powerhorse machine. So I wanted to see what anyone had suggestion-wise for scaling up this system.