For some time I have had many synchronizing issues with microsoft outlook 2013 and my bt exchange server, hence temporary elation at working through nagging and annoying sync errors, and taken me since september 2013!!!
Initially was just going to cancell then managed to get with the help of BT tech desk (credit where it is due) at least got it to work, as mail not loading
Anyway left with my system eating bandwith, Outlook at least working but was still so slow and sticking, only initial work round was opening and closing outlook when this occuring and using so much memory causing my system to freeze often which was very concerning when I got 4GB of Ram & Quad core and so on!!!!
Worked through and found Outlook 2013 send and receive specifically Send/Receive Groups>All Accounts>Edit>Microsoft Exchange> then under folder options uncheck all including default send and drafts and just leave inbox checked,
now save and close and reopen outlook and check, should see speed and importantly stability.
And no more of this lot!!!!!!!!!
00:59:35 Synchronizer Version 15.0.4569
00:59:35 Synchronizing Mailbox “_______ ______”
00:59:35 Synchronizing Hierarchy
00:59:51 Synchronizing local changes in folder 'Inbox'
00:59:51 Uploading to server `---------------------@--------------------.co.uk'
00:59:52 1 view(s)/form(s) added to online folder
00:59:52 Error synchronizing folder
00:59:52 [0-0]
00:59:52 Synchronizing local changes in folder 'Read Receipt's Received'
00:59:53 Uploading to server `-------------------------@------------------------.co.uk'
00:59:53 1 item(s) changed read-state in online folder
00:59:53 Error synchronizing folder
00:59:53 [0-0]
01:01:10 Done
01:01:10 Microsoft Exchange offline address book
01:01:10 Download successful