Thanks for helping me out Spider. As far as I know, only rules created are out of office replies.

With regards to your questions:

1) Yes. Each user is able to receive messages of other users. The messages don' actually get forwarded, they just all receive the same messages as each user's outlook has also been configured with the other 2 guys' email accounts.

2) Nope, as mentioned above, messages don't actually get forwarded

3) Whenever any user forwards any message to another guy, user A to B for instance, user C will receive it too.

4) OOA is not configured for User B & Cs' Outlook

Please advise..