I realize that many have already migrated to another program for email (instead of Netscape 7.2). However, I was asked to solve the problem of getting Netscape 7.2 email to open links in IE 7 that required a non-obvious answer (and some googling).
I am documenting it here, incase someone else wants to do the same thing.
Basically, you need to edit the prefs.js file for Netscape (C:\Documents and Settings\*username*\Application Data\Mozilla\Profiles\default\*.slt\prefs.js)
Adding the following lines:
Also, important to note that you need to have Netscape closed when editing this file… otherwise the changes will not take effect. Easiest way to ensure this, make sure that netscp.exe isn’t running in Task manager.