*.XLS files and Exchange 2010 issues using OWA
Heads up to this know issue:
ISSUE : The .xls file as an attachment is empty when you access an Exchange Server 2010 mailbox by using OWA
This is described in article 983200 on the Microsoft Knowledge Base.
The .xls file as an attachment is empty when you access an Exchange Server 2010 mailbox by using OWA
https://support.microsoft.com/?kbid=983200
Kind regards,
João Ribeiro