Calendaring agent failed with error code 0x8000ffff Event id 8206 and 8207

Question

Hi to all
We have an Exchange 2007 SP3 with Update Rollup 11 and all the user use Outlook 2003 with SP3.
Suddenly in our Exchange Server we have start to receive a lot of 8206 and 8207 EXCDO errors in the Application.
Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8206
Date:  5/2/2015
Time:  11:17:41 πμ
User:  N/A
Computer: EXCHANGESRV1
Description:
Calendaring agent failed with error code 0x8000ffff while saving appointment.
For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 48 72 53 61 76 69 6e 67   HrSaving
0008: 41 70 70 74 3a 3a 48 72   Appt::Hr
0010: 43 68 65 63 6b 50 61 74   CheckPat
0018: 74 65 72 6e 20 66 61 69   tern fai
0020: 6c 65 64 2e 20 4d 61 69   led. Mai
0028: 6c 62 6f 78 3a 56 61 73   lbox:x
0030: 73 69 6c 69 73 2e 4b 6f   xxxx.xxx
0038: 6e 74 6f 67 69 61 6e 6e   xxxxxxx
0040: 69 73 40 45 55 52 4f 43   xx@xxxx
0048: 48 41 52 54 49 4b 49 2e   xxxxxxx.
0050: 47 52                     GR     
Event Type: Error
Event Source: EXCDO
Event Category: General
Event ID: 8207
Date:  5/2/2015
Time:  11:19:41 πμ
User:  N/A
Computer: EXCHANGESRV1
Description:
Calendaring agent failed with error code 0x8000ffff while deleting appointment.
For more information, see Help and Support Center at
http://go.microsoft.com/fwlink/events.asp.
Data:
0000: 48 72 44 65 6c 65 74 69   HrDeleti
0008: 6e 67 41 70 70 74 3a 3a   ngAppt::
0010: 5f 48 72 47 65 74 42 75   _HrGetBu
0018: 73 79 49 6e 66 6f 20 66   syInfo f
0020: 61 69 6c 65 64 2e 20 4d   ailed. M
0028: 61 69 6c 62 6f 78 3a 56   ailbox:x
0030: 61 73 73 69 6c 69 73 2e   xxxx.xxx
0038: 4b 6f 6e 74 6f 67 69 61   xxxxxxxxx
0040: 6e 6e 69 73 40 45 55 52   xxx@xxx
0048: 4f 43 48 41 52 54 49 4b   xxxxxxxx
0050: 49 2e 47 52               I.GR   
All the errors come ONLY FROM 1 USER. 
How can i fix this errors?
If you require any further information do not
hesitate to let me know
Thanks and regards.

Answer 1

You must ask in Exchange forum
https://social.technet.microsoft.com/Forums/office/en-US/home?category=exchangeserver