Good evening,
OpenChange is registered as an endpoint server for Samba4. When an RPC client like Outlook connects to Samba, it first queries the endpoint mapper to know where the service is located, then initiates a connection on the temporary port where the service is bind.
You therefore need to open:
- 135/tcp (endpoint mapper)
- 1024/tcp or similar* (where openchange mapiproxy endpoint is bind)
* Samba4 sequentially assigns the tcp port depending on the port availability and order of the endpoint in the list.
If you intend to open these ports directly over the internet, I would strongly discourage you and instead advise to setup a VPN instead.
FYI, Zentyal 3.4 will be provided with Outlook Anywhere and your clients should therefore only have to open 80/tcp and 443/tcp.
Br,
Julien.