We recently migrated a client from an in-house Exchange Server (2010) to Office 365. We exported the mailboxes to PST using the workstations and imported the data back into their Office 365 profiles.
We now find that calendar entries made prior to the migration are causing issues. Opening up an entry and re-sending meeting appointments to the attendees results in an error as follows:
From: System Administrator
Sent: 20 May 2015 14:27
To: Joe Bloggs
Subject: Undeliverable: MEETING APPOINTMENT NAME
Your message did not reach some or all of the intended recipients.
Subject: FW: MEETING APPOINTMENT NAME
Sent: 20/05/2015 14:27
The following recipient(s) cannot be reached:
'Fred Soap' on 20/05/2015 14:27
This message could not be sent. Try sending the message again later, or contact your network administrator. Error is [0x80070005-00000000-00000000].
Can anyone shed any light on this issue? The error appears to suggest that the original author of the calendar entry is the previous server's user account - The new user account on Office 365 doesn't have permission to re-send this entry.
New entries work fine - it's just ones that have been imported.