Exchange Explorer Problem

Hello all, I can't get access at all to Exchange Explorer I get the below
error after I
say yes to the message 'This page is accessing information that is not under
it's control. This poses a security risk. Do you want to continue.' I click
yes and I get: -

'Server not available or a unrecoverable error occurred"


I can't get into exchange explorer at all, I've tried administrator accounts
as the username and pass and also accounts like exmerge which I gave access
to all accounts, I've tried going to just server/exchange and
exchange/mailbox using the mailbox I'm trying to get to's username and
password.

What access do I need exactly, or is this not a permissions problem?

I had sbs2003 and ran in the Transition Pack to move to Server 2003

I've tried the below url's for all the above usernames.

http://server1/exchange/mailbox
http://server1/exchange/mailbox/folder
http://server1/public
https://server1/exchange/mailbox
https://server1/exchange/mailbox/folder
https://server1/public
http://server1.domain.local/exchange/mailbox
http://server1.domain.local/exchange/mailbox/folder
http://server1.domain.local/public
https://server1.domain.local/exchange/mailbox
https://server1.domain.local/exchange/mailbox/folder
https://server1.domain.local/public

Any help would be greatly appreciated, I need to put in an event sink asap
and it's been waiting about 3 months and can't wait any longer!

Thanks