Well, the gmail connection issue is very odd. Have you set your installation to send notifications to the users through a gmail account? Otherwise, if you have not set any gmail account at all, it makes no sense at all.. Where have you downloaded your Feng Office version from? The links provided by us, right? Which one is it by the way?
Regarding the file permissions, I would try 755 for all of the contents in the upload folder.. may be even 777 if needed.
Best regards,
Francisco