Outlook 2010: Meeting cannot be changed

In an Outlook 2010 / Exchange 2007 (SBS 2008) environment we habve on euser and (at least) one meeting where we can't change this meeting.

If the owner of the meeting changes the meeting she receives no immediate error meessage but her inbox shows a few moments later for all participants <firstname> <lastname> of the meeting:


Fehler bei der Nachrichtenzustellung an folgende Empfänger oder Gruppen:

<firstname> <lastname>
Sie können keine Nachrichten im Auftrag eines anderen Absenders senden, sofern Sie keine entsprechende Berechtigung besitzen. Stellen Sie sicher, dass Sie die Nachricht im Auftrag des richtigen Absenders senden, oder fordern Sie die entsprechende Berechtigung an. Falls das Problem weiterhin besteht, wenden Sie sich an den Helpdesk.

Diagnoseinformationen für Administratoren:

Generierender Server:

#MSEXCH:MSExchangeIS:/DC=local/DC=<server>[578:0x000004DC:0x0000001D] #EX#


The participants of the meeting do not receive any change notification.

New meetings can be created and modified with no problem.

What does this "504" stand for?

Many thanks
Who is Participating?
Olaf De CeusterCommented:
What if try doing it from Outlook Web access? Does that work?
https://remote.your domain
sg08234Author Commented:
With OWA I receive:

You don't have the necessary permissions for sending mails from this mailbox

As I can create and modify new meetings with no problems from this mailbox there must be a specific property with this special meeting item --> How can I explore all properties of a meeting?

Thanks - Michael
Olaf De CeusterCommented:
In Exchange Management>Users assign yourself full management permissions to the mailbox.
If this is your mailbox and user was created with the SBS console add user wizard you can run the user template and it will reset ll permission correctly.
If its someone elses mailbox you have to change permissions in the exchange management console.
Hope that fixes it.
Sounds like a corrupt appointment

Is this appointment a recurring appointment?
POssibly one that has no end date?
If it is, its quite common for these to become corrupt over time
See if you can set the end date to today
Then simpy create a new appointment and go from there
Be sure to set an end date though, say about a year out

If its not a reucrring appointment it can still be a single instance of a corrupt appointment
check to see if cached exhchane mode is on
If it is, turn it off and try deleting the appointment

if that doenst work
close and open outlook using
start>run>outlook.exe /safe

see if you can delete it here

Alternativley may need to get an exchange admin to open the calendar and delete the appointment directly
Also something else might need to consider

Where is this calendar?
Is the the user main calendar or is this an clendar thats in a personl folder

If its in a personl folder, close the personl folder
Run scan pst over it
then open it back up in outlook and see if you can delete the appointment
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