1.) Start an SMTP server on port 2525 (for example FakeSMTP).
2.) Start your portal and in Sever Administration configure the SMTP server.
3.) Navigate to your welcome page and place a Documents and Media portlet to the page, in this portlet create a folder and a sub-folder, subscribe to the folder, by making this action you will automatically subscribe to the sub-folder as well.
4.) Copy the URL of your sub folder and connect to the location via WebDav in your Windows explorer.
5.) When you see the right path copy an excel file to the folder.
Checkpoint: You will see that your user is notified that a new file was uploaded.
6.) Open the file in Windows.
Result: You will see that two new messages are sent to your user, one is that a new file was uploaded and another that the file was modified.
The file notifications are sent because a new temporary file is created while editing the specific file