A trigger folder is simply a Windows folder that Easy2Sync watches for changes. if any file is changed by any application, a sync can be started. The folders that are being watches (up to 2) can be identical with the synchronized folders, but don't need to be. If you want to watch the synchronized folders, you can simply enter an asterisk ("*") as path.
Some NAS devices have a bug regarding this function. They correctly report a change in the trigger folder to Easy2Sync, but they do not notify Easy2Sync for changes in subfolders. This is not Easy2Sync's fault, only the manufacturer of the NAS can fix this bug.
A trigger file is a file which existence is enough to let Easy2Sync start the synchronization of a certain task. The contents of the file do not matter. As soon as Easy2Sync finds the file, it will be deleted.
You can use this to start a synchronization when another computer is started. For this create a text file with the name "Trigger.bat" and write the following text into it: "@echo "test" >FILENAME". You may choose any file for this, as long as you also enter the filename on this computer into Easy2Sync. If there are spaces in the path, you must enclose path and filename in quotation marks. Now simply create a shortcut to the file in the startup folder.