You can block IPs belonging to Google, Micorsoft, ... And make the link expire after a while (you can keep the content, just make it inaccessible). Not foolpro

You can block IPs belonging to Google, Micorsoft, ... And make the link expire after a while (you can keep the content, just make it inaccessible). Not foolproof or without problems (there are not only crawlers and bots at these companies, there are also people who receive email), it would solve the problem in most cases.