SkySync's filters are applied near the very end of pre-run preparations. Because of this, you may still get error notifications for files that are going to be filtered out.
Case Study:
Files that have been specifically filtered out are still receiving errors when a job is run. An example of this is a file that is of a unsupported size, getting an unsupported size error, but is already being filtered out of the job because it is a movie file. This is a known issue and is due to the fact that filters are run last when a job is executed. This means that if an unsupported file is present in one of the connectors used in a job, then an error will still occur alerting you of this. The filter will also still prevent the file from moving but not before the error is triggered.
Future Plans: At this time there is no plan to fix this issue in the current version of SkySync, however it will be fixed in the next generation of the product. If you are having issues with email notifications it is advised to setup a filter in the email program alerting to that specific file.