Sluggish Page Loads

One of our clients has 150-200 user accounts (mailboxes). Most of these accounts are new and empty. However, it takes an unreasonably long amount of time to display any of the editing pages in his account. Even clicking on "Edit Virtual Server" takes over a minute to load. It pauses before the line "Mailbox name prefix", presumably because it's counting the number of accounts. The edit user and alias pages take even longer to load, like 2-3 minutes.

Is there any way to optimize the display of these pages so the appear more quickly? The server has available memory, swap, disk space, and CPU load is usually under 1, so it doesn't appear to be a hardware problem.

Closed (fixed)