E-mail notofication via internal network

Hello community!
I have encountered with issue: can’t setup notifications via e-mail.

I have installed Kanboard on the PC which is conected to local network of our company (now this PC is server for Kanboard system, i using xammp to create server).

All users getting access to Kanboard by adress “ip of my PC/kanboard”.

In our company we have separate dedicated server for internal e-mail.

What i have to do to setup sending of notifications from kanboard to this local e-mail system?

Thank’s in advance for any help.