The only thing I can think of is to rename the sendmail.dll in
C:\Windows\System32 folder. This will disable both the Send Link and Send
Page operations. No warning messages will pop-up, just nothing will happen.
Sending regular email via OE will not be affected, as I have tested this.
You'll have to get around Windows Files Protection to do this:
1. Close all IE and OE windows.
2. Rename the sendmail.dll file in C:\WINDOWS\system32\dllcache with an .old
extension
(Note: Since the folder is a compressed system folder, you may have to
disable the "Hide protected operating system files" option in the folder
options - Control Panel...Folder Options...View tab - to see the folder.)
3. Rename sendmail.dll in C:\Windows\System32 folder with an .old extension.
Or just delete that file. Windows File Protection may complain, just click
Cancel, and then click Yes to the next pop-up dialog box.
To restore the functionality, just rename the sendmail.old file from the
dllcache folder back to the .dll extension and copy it to the system32
folder.
Replacing files protected by the Windows File Protection
http://support.microsoft.com/kb/555486/en-us