Hi, I have the same problem loading a folder with huge amount of messages (around 80.000). I tried to change some IMAP (courier) settings and one of them improves the load (from 1 min to 5 sec aprox). This setting is the IMAP_DISABLETHREADSORT which in my daemon configuration (in /usr/lib/courier-imap/etc/imapd) is default setted as 0. If i change it to 1 the performance is much better.
There are two problems, tough. First, the server's workload rises over the average, but I'm not completely if this is due to the change.
The second is the messages sorting. As I have changes the variable the server does not do the sorting so it's up to the client. It seems that the client doesn't do it and messages appear with no logical order.
Do anyone know anything about it?