An administrator asked about a policy solution to prevent users from clicking on links in email.
While you can't prevent users from clicking on links, you can take advantage of a fairly common problem to make the links unusable. This won't stop clever users from copying the links and pasting them into the browser but it will slow them down, hopefully, slow them down enough to make them think.
Most users want to fix the “This operation has been cancelled due to restrictions in effect on this computer.” error, but you can force this error in Outlook (and other programs) by editing a registry key:
Rename or delete the command key found at
Once you do this, users will get an annoying error when they click on links in email and other applications. Links will work as expected within the browser and users can copy and paste the links into a browser to view them.
On a related note, its also possible to block users from opening specific attachments, either by blocking them completely, as if they were exe attachments, or by forcing users to save them to the hard drive before opening. We have instructions for using the Level1Add and Level1Remove keys at Block Additional Attachment Types.