Hi,

I am receiving below emails time to time in my unread folder of Outlook and no clue what is this about; Is it Exchange server end issue or an Outlook issue?

10:55:44 Synchronizer Version 15.0.4719

10:55:44 Synchronizing Mailbox 'name'

10:55:44 Synchronizing local changes in folder 'Sent Items'

10:55:44 Uploading to server 'Exchange Server Name' 10:55:44            1 item(s) added to online folder 10:55:44 Downloading from server 'Exchange Server name' 10:55:44 Error synchronizing folder 10:55:44
[80040109-50A-80040109-560] 10:55:44                  The function cannot be performed because the message has been changed. 10:55:44                  Microsoft Exchange Information Store 10:55:44                  For more information on this failure, click the URL below: 10:55:44                  http://www.microsoft.com/support/prodredirect/outlook2000_us.asp?err=80040109-50a-80040109-560 10:55:44
Done

This happens usually when you have multiple devices setup to connect to your exchange account.  We have users that have Outlook setup as well as 2 or 3 mobile devices connecting to their mailbox through ActiveSync. If one those mobile devices changes the message ever so slightly (usually it's a timestamp that off by nano seconds) you will see these sync issues.

Thanks for your reply Corey,

Being an Exchange Admin, Do I have to worry about these issues at Server level? It seems ost issue isn't it?

I wouldn't be concerned with it.  Microsoft states that in most cases you can safely ignore these messages.  In some cases where the sync errors don't go away, it could be related to a corrupted message.  If you keep seeing the warnings about the same item, try creating a second Outlook profile to test with and see if the error still occurs.  You can also attempt a mailbox repair.

9 times out of 10 though, the sync errors will clear up on their own.

• Marked as answer by techtiger Friday, June 19, 2015 6:32 PM

Thank you very much for explanation.

One more issue, I have been facing in the user mailbox unread emails is below;

The message with the subject 'Bla bla bla on 29 Nov 2014' existsin your mailbox on Microsoft Exchange but not in your Outlook data file (.ost).

Can you please put some lights on it.?

That sounds like a corrupted OST file.  Outlook has an OST Repair tool you can run against it.

• Marked as answer by techtiger Friday, June 19, 2015 6:32 PM