Hello Everyone,
I am in the process of designing a mail system for my company.
There are two Servers: Server1 has a public IP address and is connected to the internet directly; Server2 has a private IP address and is connected to Server1 via a corporate network. Both servers have Zimbra 8 installed. Users are on the same network with Server2.

The requirements are as follows:

- Mails are sent locally between users via Server2. (For example user1@domain.com, user2@domain.com)
- Users can send mails to external email addresses (like friend1@gmail.com, friend2@yahoo.com) via Server2 which can use Server1 as a smtp relay.
- Users can receive mails sent to their email addresses from external e-mail addresses.
- Users can access their mail boxes when they are out of the office.

The reason for this setup is that the corporate network connection between Server2 and Server1 has limited bandwidth. My company is trying to reduce the bandwitdh usage on the corporate network link by having intra-office communication handled locally.
"Why should a user connect to a remote server on the corporate network or internet when they are communicating with someone two offices away?"

I will like to know if this kind of setup is possible with zimbra and what kind of configuration will be required.
Suggestions of a better solutiion to this problem are also welcome.

Thank you for your help.