The drop folder setting doesn't allow the path to be edited in the SMTP properties dialog.
How do I change the drop folder?
Plesk keeps changing the permissions on the default drop folder and it prevents my web apps from functioning properly. They aren't allowed to write email to the folder after Plesk resets the permissions of the folder. I have to manually fix this every so often when this happens. If I can change the folder to a different location, it should resolve the issue.