I believe since moving to the native Boxcryptor Mac OS X version from the Macfusion solution I've seen problems when opening files from Finder that I have saved from Outlook 2011 - attachments to email messages mainly.
The error message is "<file name> is damaged and can't be opened. You should move it to the Trash. Microsoft Outlook downloaded this file <some day> at XX.XX*.
Opening the file from within e.g. Microsoft Excel works fine but not when hitting CMD-O from Finder.
Please advise how to solve this issue.