EMAIL DOWNLOAD ARCHIVE

I want to download my all accumulated emails in my inbox so I can delete them from the server and regain space. I looked up help for roundcube, but they give instructions for a button (download) which is supposed to be in the manage folders/GEAR menu, but I don't dee it.

I also tried selecting all the emails in the inbox, but when I tell it to download from the there, it spins for about 5 minutes and stops, but I don't know if/where it is actually downloading the zip archive?

I have had this email for years and I keep deleting unneeded emails, but I would like to just archive/zip the entire inbox, leaving the other email folders intact. Help!