Its notifying users a couple of months beforehand.
There are still a lot of users out there running older builds of Mac. One of the biggest reason for this is hardware incompatibility. Some older Mac machines are not compatible with the more recent builds of the desktop software so that’s as far as users can go on their computers.
Those who are still running a Mac with OS X 10.5 should note that Dropbox has announced it is going to stop supporting this build. The cloud storage company has started sending emails to users notifying them that from May 18th, 2015 it will stop supporting OS X 10.5 and older versions.
Users who are still running these builds on their computers will not be able to use the official Dropbox app until and unless they switch up to more recent builds. For that some might have to change their machines, others just might get away with a simple software update.
Dropbox clarifies that end of support doesn’t mean that users’ files and folders will be deleted from their cloud accounts. They will continue to exist and will remain accessible through supported mobile devices. Users may continue to use the service through its web portal after May 18th, but once that they arrives, they’ll be signed out of their account on the desktop app which will then become unusable.