We're a school that wants to offer our pupils, when they leave, a separate email address so that we can easily keep in contact with them.
I've added a second accepted domain into our Exchange Organisation and have set up email addresses for these now ex-pupils using their same AD account. They just have a new b.com email addresses instead of a.com. This is tested and works fine.
They are hidden from our address list so that they don't appear in the GAL but what we would like to do is separate these accounts so that they can only browse a GAL of ex-pupils.
We need to do this otherwise we would be providing adults from outside the school with access to children via the email's GAL. That's why it's important to come up with some sort of solution.
I've read an article from Rui Silva at MSexchange.org that talks about shared hosting but the author is quick to point out that this is neither supported or recommended by Microsoft. Email is too business critical to implement something on the server which is unsupported.
So is there an official way of doing this? Any help/advice would be greatly appreciated.