I have 3 accounts configured:

IMAP - work email address
@hotmail.com
@live.co.uk

I get all the emails through on my device for the 2 hotmail accounts but on the IMAP account, roughly 10% of emails that appear in Outlook do not appear on my device. Also I notice that on the IMAP account, the mails regularly dissapear after a number of hours, so this morning my IMAP inbox was empty but I hadn't deleted any.

I've been on the Blackberry Internet Service and unticked "synchronise deleted items" on the IMAP account - would that solve the emails deleting themselves automatically, but I'm at a loss to understand why I'm not getting roughly 10% of the emails from that account on my device?

Dont know whether this is the same for IMAP, but once the emails are downloaded to outlook, are they not then off the server? so BIS poll's the server and finds none because outlook downloaded them?

Do you have "Leave Mail On Server" checked in your Outlook advanced settings?

Some email comes to my BB and some does not - BlackBerryFAQ