Giving a user in one domain access to a mailbox in another domain

[Ant-nee]

All,

I have a small network set up at a company. There are two domains set up,
hence two Exchange implementations.

A user in Domain A needs access to a user's mailbox in Domain B. There are
no trusts set up.

Is there a way to grant this access to the user in Domain A without setting
up trusts?

 

[F.H. Muffman]

I have a small network set up at a company. There are two domains set

up, hence two Exchange implementations.

A user in Domain A needs access to a user's mailbox in Domain B.
There are no trusts set up.

Is there a way to grant this access to the user in Domain A without
setting up trusts?

Not in any version of Exchange that I'm aware of.

I mean, if it's two different Exchange organizations, you can't do anything
through Outlook. Selecting other users (at least for selecting the mailbox
to open) requires picking a user from the domain in the GAL.

If it's two different domains without a trust, then there's not even a way
to assign permissions on the Exchange side, since you assign permissions
to a domain account and without a trust, there's no accessing the directory
on the other side.

You could create a user in Domain B for DomA\User and give DomB\User permissions
to the applicable mailbox and have them use OWA, that's about it.