got a SonyEricsson Xperia X1 (Win Mobile 6.1) with similar problem as previously described in
When running Activesync it syncs Calendar, Contacs etc. just fine and even lists all inbox folders, but inbox is showing 0 items.
Have done the same on like 10 users with no problem whatsoever (same Exchange 2003 server).
Not a particularly big mbx (ca. 250 Mb), but got a lot of folders directly under mailmbx root.
Sending email works just fine, but it's not showing up in Sent Items.
Also tried to syncing the inbox with an SonyEricsson P1i that uses the Dataviz version of activesync and there is no problem at all synching the mail with it.
Anybody got any clues?