David Gwynne-Evans wrote:

When I try to open Outlook will either freeze or give message "The
server did not respond to this IMAP command before the connection was
terminated". I did not have similar problems with the previous
version of Office. I am however now running Bull Guard security so
could this be a problem. I don't have difficulty in opening
attachments up to 1mb but can't open anything larger than that.

Try lengthening the server timeout value on the Advanced tab of the account
properties. Also consider enabling the option to download the entire
message rather than just the headers in the Send/Receive Group settings. In
order to ope an attachment on the IMAP server, Outlook must download the
message first and it appears the attachment is large enough the the
connection times out prior to obtaining the entire message.
--
Brian Tillman