I noticed a bug in the Runbox 7 folder management.
I created some folders under my account. I mean the root was ‘account’-‘folder A’, etc.
I then rearranged the root in the webmail this way: ‘account’-Inbox’-‘folder A’. So I moved my folder(s) under the inbox. They basically became Inbox subfolders.
After this change I noticed that in Runbox 7 something went wrong. If I click on a folder in Runbox 7 some email are not displayed anymore. So I have a folder with 6 mails and I can see all of them, but I have another one with 2, but just 1 is displayed, another with just 1 mail and seems to be empty instead.
If I switch to Runbox webmail everything seems to be ok.