I am trying to share (with full permissions) calendars across two different exchange servers in two locations. So here is the setup:
1 x Exchange 2007 (location 1)
1 x Exchange 2003 (location 2)
Different versions of Outlook (ie Outlook 2003/7)
Localised GAL for each server (so they are not shared).
There is no VPN between the two servers but that can be setup.
They are not part of the same domain, forest etc.
Basically I want to add/edit/delete events on some other users account in the exchange 2003 server from location 1.
I googled and found that there are a few ways this can be done but no definite solution. These include using webDAV (but I think this only work with outlook 2007) and merging the 2 exchange servers.
I am also a bit new at using Exchange, so I am still trying understand how the 'black box' actually works.
Best Answer
As mentioned by LEAT, to do this you will need to setup a trust between your two seperate Active Directory Forests. Firstly, you will need a link between the Forests, in your case it looks like your going for a VPN, once thats up you will need to setup your DNS on both domains so that the Exchange servers can resolve each other.
Once that is done you need to create the actual trust. There are two possible types of trust you can use here, an external trust, or a Forest trust.
To set one of these options up, take a look at one of these articles: