It looks like I'm running into the next problem. I solved the new-moverequest problem. The move-request is running but unfortunately again with error messages. Here a part of the log with the errors.
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:47:19 [AMSPR05MB050] Mailbox signature will not be preserved for mailbox 'Primary (5f705e32-26e1-45c1-a8fe-d56aa835555a)'. Outlook clients will need to restart to access the moved mailbox.
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:47:20 [AMSPR05MB050] Stage: CreatingFolderHierarchy. Percent complete: 10.
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:47:20 [AMSPR05MB050] Initializing folder hierarchy from mailbox 'Primary (5f705e32-26e1-45c1-a8fe-d56aa835555a)': 504 folders total.
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:47:20 [AMSPR05MB050] Folder creation progress: 0 folders created in mailbox 'Primary (5f705e32-26e1-45c1-a8fe-d56aa835555a)'.
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:49:38 [AMSPR05MB050] Transient error TimeoutErrorTransientException has occurred. The system will retry (1/60).
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:50:09 [AMSPR05MB050] The Microsoft Exchange Mailbox Replication service 'AMSPR05MB050.eurprd05.prod.outlook.com' (15.0.702.14 caps:3F) is examining the request.
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:50:49 [AMSPR05MB050] Connected to source mailbox 'Primary (5f705e32-26e1-45c1-a8fe-d56aa835555a)', database 'EURPR05DG004-db064', Mailbox server 'AMSPR05MB050.eurprd05.prod.outlook.com' Version 15.0 (Build 702.0).
19-6-2013 22:51:16 [SERVERNAME] 19-6-2013 20:50:49 [AMSPR05MB050] Transient error CommunicationErrorTransientException has occurred. The system will retry (2/60).
Do you have any tips on these error messages? I already checked our ISA server for flood messages, but could not find any from a O365 ip address.