Recently the "send link to mail recipient" feature stopped working on my Windows 98 system. Tried lots of stuff to fix it but finally found one procedure that brought it back:

If Mail Recipient is missing when you click Send To on the File menu, follow these steps to install Windows Messaging:


Quit all Windows applications.
Install the Windows Messaging component (Wms.exe) located on your Windows 98 CD-ROM in the following folder:
:\Tools\Oldwin95\Message\US\
NOTE: Double-click the Wms.exe file to start the Windows Messaging Setup program.
After Windows Messaging Setup is complete, restart Windows.
That did the trick for me.