An email site like that is considered a 'Secure' site. Only people with the correct credentials will be able to view it.
Secure sites usually open within a 'session' assigned to the user that entered the correct details. Your session only applies to you, hence you could return to the link. You probably still can.
No-one else though was having a session with you. Well, perhaps they were, but it isn't my place to pry!
Seriously, think of a session as your own webpage; it exists for no-one else at that particular time. Same as a shopping basket in online shopping.
So in conclusion, that file needs hosting on a public webpage. Send it me and I'll stick it on mine if you like.