If you want to use qk on two machines, here is an answer for you to refer to:

First, the local SMTP Server should have an IP address or a domain
name which can be accessed, moreover you should have a SMTP Server
port which the local firewall allows to access;
Second, SMTP Server don't deny others' access.

127.0.0.1 is always the local address, you can't use it to access
other computer. If you want to access the local host, you should
remember the IP address or the domain name on the internet for the
local host.

Moreover, QK SMTP Server' s default configuration only allow the local
IP access. So, when you use it on the road, you should add an IP
address which others can access, in Settings -> Access IP Control . If
you don' t know this IP address, you can choose ' IP address not in
table ' to ALLOW. Considering the safty you can add a account and
password in order to make the QK SMTP Server needs verify.

I will give you an example now. e.g.: QK is installed on the server
(the IP of server is: 166.168.0.119). A computer "D" (IP of D:
166.168.0.9) want to access and use QK. The configuration of server
is: allowing the IP 166.168.0.9 to access. The configuration of "D"
is: the SMTP address changes to the IP of server 166.168.0.119 ( not
the default one --- 127.0.0.1 and this is uesed in the server).
__________________