Data Protection> Action > Route To

Hi

I would like to know if the following scenario is valid once a customer have deployed EmailSecurity.Cloud:

1. A Policy will be triggered if the subject contains a specific keyword.

2. Action will be Route to a onsite MTA

  2.1 Onsite firewall will allow smtp inbound traffic from Message Labs and redirect to the internal MTA.

Question:

- This kind of situation will work?

Thanks