Last weekend I started our cutover migration batch. Yesterday the batch was finished. No one is accessing their Office 365 mailboxes yet, but today we received reports from customers that they were bombarded with automatic no-read notifications for several mails they sent a long time ago. From the message headers, these mails were sent from the Office 365 servers. You know, those automatic replies from Outlook when a message has a 'read' notification attached and the message was deleted without reading. Any idea why these messages where sent out for mails which were sent to the mailboxes in the past, there were reports from no-read messages on mails from december 2012. The messgaes were sent out last night, but no-one had access to their exchange online messages yet. Archiving isn't enabled on the mailboxes so that can't be the cause to. What's happening here?
Franc.