How often does my OPML source list get backed up?
Your Feedly sources will automatically be backed up when you add, edit or remove sources or feeds, so you can keep a history of your subscriptions.
A new file will be created for each day you changes your subscriptions. If you make multiple changes on the same day, only the last change will be kept.
Deleting OPML files from your Dropbox does not impact your Feedly.