Here is a handy plugin that makes it easier to share and send files in WordPress. SiteDrive support public and private drives. You will be able to move your pages and content around. Once you create your drive, you can change its thumbnail, name, password, visibility, and other settings. You can connect to drives on your own site or another site. Once you receive a file, you can push it to the endpoint directly.
SiteDrive just needs the receiving and sending site to have the plugin installed. This plugin has a sync feature, which means you get notified when a file you have on your site has been updated. SiteDrive lets you send any file type, including zip files and PDFs. It also supports custom files and post types. THEMECO is the developer behind this plugin.