An external user (suppose his email id is: email@example.com) forwards a mail containing a registration link to UserA@acme.com (UserA/Acme)
Then UserA/Acme forwards that link to UserB/Acme (internal user)
UserB/Acme then checks the mail in notes client and the link appears in the form of a blinking underline.
When he drags and drops the mail from his mailfile to his desktop, the link becomes visible. Need to improvise this situation.