In fact, I did that on 3 complete different SBS 2003 servers.
On 2 it worked and on 1 it didn’t.
First my user logs on at [url]https://url/exchange[/url] and sees his own mailbox.
Then the user goes to [url]https://url/exchange/other[/url] and he gets the following error :
The page cannot be found
The page you are looking for might have been removed, had its name changed, or is temporarily unavailable.
HTTP Error 404 – File or directory not found.