Outlook anywhere & 3rd party SSL,

Hi all,

I have a brand new forest/domain . I install windows 2008 R2 and Exchange 2010 sp2(all roles in 1). There is no existing exchange server.

When connecting outlook from internet to the exchange, i have the "the connection to microsoft exchange is unavailable".   I have check the encryption setting and http proxy, they are all in placed.

When connecting the outlook within the intranet, there is no problem. Please note that the client is not joined to the domain.

Question :

1: is it compulsory to have a 3rd party certificate in place? this is in a testing stage, hence i haven't got myself a 3rd party cert

2: anything else i need to verify on the exchange server side to ensure outlook anywhere is working for external client?

Thanks.