The Azure Information Protection client (classic) is the original downloadable client for organizations that use Azure Information Protection to classify and protect documents and emails, or use a Rights Management service to protect their data.
If the API client is not installed on your machine then it can be installed from: https://www.microsoft.com/en-us/download/details.aspx?id=53018
One should use the classic version of the AIP client. When you press the Download button, select AzInfoProtection.exe.
To classify documents, you can right-click on a document and select “Classify and protect”.
Log in with email@example.com if prompted.
Then select the most suitable classification for the selected document.
You can find more useful information about classification of files here.
If you work from a Mac and are going to classify, you can do this through the Student Home Office. The AIP client should be installed there.