Situation:

-Customer has taken over an existing company.

-New users where created in the domain.

-Mail accounts where created and the .pst's imported.

-Everything fine so far.

Problem:

When a user tries to edit a calendar item created in the past the message "You don't have the permission required to send messages from this mailbox" appears. After that the item is changed in the users calendar who edited the item but not in the other users calendar who where also invited.

Everything works fine when a new calendar item is generated.

Cannot find anything on this.

Please help!!

Sound like they are trying to update meetings for which they are not the organizer? Do they have access to the calendar/mailbox of the organizer?

I guess it will be easier if you just recreate the meetings.

They are the organizer of the items they want to modify. 

I already suggested to recreate those items but that was not an option because there are a lot of recuring appointments.

The customer wants it fixed, but I am stuck on this one.

Hi,

According to your description, I understand that you create a new mailbox for a user and imported Calendar items to this mailbox by using PST file.

If that is the case, the calendar items which are imported should be created by other user. It is just imported in this mailbox. Please check whether the original mailbox which these calendar items created on is still existed in Exchange server or not. Then check the calendar items in the original mailbox.

Additionally, if the original user is still existed in your AD or exchange server, please assign Send As permission for the new user to this mailbox to have a try.

Regards,

I have no access to the AD or Exchange environment of the previous hoster. The users and mailadresses where created in the AD of the new company. The previous hoster delivered the .pst files which I imported in to the new mailboxes.

I already tested with Send As permissons, that is working perfect.

The users keep telling me that they are the ones who created the items.

I went through this when we migrated from 2003 to 2010. There isn't anything to do but recreate the meetings. The objects are looking for something that isn't there anymore in AD.