#007FFF

Symptom
User not able to open the Word document in Word Web App | View Browser received Error: "Microsoft Word Web App - Word Web App encountered an unexpected error."  while connecting to Office 365 environment from a Windows XP SP3 / Office 2010 / IE 7 with Silverlight Add-On enabled

Description 
Disabling mailboxes on premise results in deletion of mailboxes in the cloud via DirSync. If a restore request is made within 30 days, the following procedure can be used to merge the content of the previous RemovedMailbox into an existing mailbox.
***WARNING*** because this is merging data from mailbox into another mailbox, care must be taken to verify both source and destinations before executing this procedure.

resources about Office 365 bandwidth for reference.  
Company Network Requirements
http://www.microsoft.com/online/help/en-us/helphowto/3dea7174-a521-4442-a7c5-5d540e09b20d.htm