Dropbox for Linux has the annoying habit to send a desktop notification every few hours telling me that my space is almost full. Is there a way (under Gnome-based Ubuntu 17.10 and newer) to filter out this message, while retaining all other notifications (both from Dropbox and other programs)?
Notifications work using Dbus, if I understand correctly, so I wonder if there is a way to 'intercept' this call to filter it out without having to patch and recompile Gnome.
I don't have DropBox installed, but here's how you can configure Gnome3 desktop notifications per application:
On re-reading your question, I see you want to retain other DropBox notifications - so this isn't the answer you're looking for. I've asked much the same question (but phrased more generically) at Does Gnome3 have a method to filter desktop notifications?