We have an exchange server 2003 running locally. When Staff A sends mail to Staff B, the server just delivers it locally. When staff A sends mail to an external email address, the server sends it to our cloud server, which then forwards to the destination.
Each staff has an account in the cloud server, and also an exchange account.
Users can access their webmail for the cloud account (tho they only seen mails from external sources)
Problem is, I want a situation where Staff A sends a mail to Staff B, the exchange server delivers it locally, and also delivers to the POP cloud server