Like the Topic says:
Our Exchange Server accidentally forwards sent mails from one User to another User's Inbox.
The sent mails are mostly to Outbound Adresses and they where successfully delivered but all those sent Mails are accidentally forwarded into our Info Mail account.
There are no Outlook rules defined and the forward routing in exchange is not used, for such things.
I really don´t know the cause of the problem and i don´t know where I have to look, because I´m new to exchange...