Hi,
exuse me if this question already was in phorums. But I have some specific situation.
I have SME server behind router. Router is from my ISP and I can not controle it.
In remote office router is controled by me. How can I allow my remote office workstation to access SME for POP only. For SMTP they will use ISP server.
I am new in Linux, so please more details

.
Thank you.