Trust Relationship between two Windows domain

[zuma.net]

I have two seperate locations connected thru VPN.

Site A Domain A w2003
Site B Domain B w2003

I want to set up trust.
If understand corectly:
Add forwarder to DNS Domain on both sides Name and IP
Add each side two way in trust Applet

Do I have to raise both to w2003, one is and one is not,

I am afraid that it might affect my current setup,

Current setup:
Site A has Exch 2003
Site B connects acroos VPN to exch 2003

New config is to reverse and have Site B host Ex 2003

When I try to connect to new Exch on other domain it wont acceptin utlook,
it populates local AD Exch.

If I make a trust will it then be able to reach new Exch on other Domain?

Thank you in advance

[Phillip Windell]

1. It would have to be a Conditional Forwarder in DNS or you will get an
endless loop.

2. Each site is going to be a different Subnet.

3. Exchange has nothing to do with Subnets

4. Domains have nothing to do with Subnets

5. Exchange only cares about Domains,..and the Mailboxes exist in AD in the
Domain,...not on the Exchange itself. It doesn't matter where it is
physically located or what subnet it is in.

[Phillip Windell]

To clarify that, a mailbox is "imaginary",..it is nothing more than an
Active Directory Attribute of an Object (in this example, a user object).
The actual data associated with the User account (via the Mailbox Attribute)
is stored in the Information Store on the Exchange Server.

So it is a complex integrated system.

So how do I reach the other Exchange server 2007 if it is on a seperate Domain?

[Phillip Windell]

I don't think you understand the situation.
You don't reach an Exchange Server "on a Domain",...you reach the Exchange
Server "on a network". Domains are not "networks". Domains are
"administrative environments".

The user and the Exchange are going to be on the same Domain togther to
start with.
The user has to use the Exchange that is in the same Domain (administrative
environment) that the user is in.

To make it more clear,...you can't have one Exchange and two Domains.
You must have two Exchanges if you have two Domains (one Exchange in each
Domain). Exchange is "married" to the Domain it operates in,...and it
doesn't cheat on its husband.

Now you can have multiple Exchanges from different Domains operate together
in the same Exchange Organization if the two Domains are in the same Forest
(like in a Root Domain/Child Domain situation).

You can have multiple Exchanges in one Domain or Forest

But you cannot have one Exchange in multiple Domains or Forests.

[zuma.net]

I understand what you are saying, ea domain needs its own exch. Server.

I had the users in the other domain connecting to the Ex 2003 with no
problem. This way they had full exch features from both domains. These are
..local domains.

I would create the user in both domains so they would be able to
authenticate, user name and password.

If I set up a trust, will that allow connectivity?

[Phillip Windell]

Look...

You have 2 Sites,...a Domain in each Site

Therefore you need 2 Exchanges,....one in each site/domain.

If both Domains are in the same Forest the two Exchanges can be in the same
Exchange Organization, but if it is not the same Forest then that is not
possible.

How can I make them both in the same forest now, can I create a trust?

[Phillip Windell]

You can't.

You have to create a new Domain within one of the existing Forests then
migrate the users from the left-over Domain into it.

Or create a whole new Forest with completely new Domains and migrate the
users from the old domains into the new ones.

Or just have one Forest with one Domain and forget it. Migrate everyone
into it.

This is why this stuff requires knowledge and planning before you commit
yourself to doing something that can't be done.

[hamedhemmati]

it's actually very simple. you have two options and none of them require any kind of trusts. first thing that you need to do is to create mailboxes for those that are in the other domain within exchange and make sure the username and passwords are the same. now you have two options for connecting to exchange from the other domain. if you have a vpn tunnel you can just setup your outlook to connect to the exchange server through the tunnel but i suggest you go with outlook anywhere since you got exchange 2007. enable outlook anywhere and make sure all your dns settings are correct then you can setup your outlooks to use outlook anywhere this way you keep your vpn tunnel open for other file transfers.