Thanks for this excellent add-on! I suggest to add this as a component to Roundcube - maybe as an optional extension that can be enabled through the main config file.
Good job, have been looking for something like that for a while!
Now a question: I am trying to use the whitelist_sync feature but somehow it doesn't seem to work - or it works differently than I expect it to.
If I added a user to my addressbook, should it be added as a whitelist user to the userprefs? I did add the contact_id field for the table but it's always -1 no matter where I add the user (addressbook, add via + symbol at email, whitelist rule).
I can live without this feature, everything else works great! Just wondering what this feature will add to RC and the Whitelists
EDIT: Never mind, without me doing anything the sync now works when adding something to the addressbook. Which makes this thing even BETTER!