Hi,
I'm testing currently the rc 0.8 beta on nginx and I got issues when I try to preview or download images, doc, docx, etc files. The only ones which appear to work are pdfs, txt and files based on xml like svg.
When I download the attachment with e.g. thunderbird everything is ok, so is it a bug in rc 0.8 beta because it is working with roundcube 0.7.2.