Setup/network-checks.sh: line 42: nc: command not found

i am trying to install mail-in-a-box on my vps but getting below error. i have checked my port 25 show me telnet localhost 25 “220 code” but yet not allow me to install.

setup/network-checks.sh: line 42: nc: command not found

Outbound mail (port 25) seems to be blocked by your network.

You will not be able to send mail using this machine, so setup
cannot continue.

Many residential networks block port 25 to prevent hijacked
machines from being able to send spam. I just tried to connect
to Google’s mail server on port 25 but the connection did not
succeed.

Hi & sorry for the problem.

It’s been fixed in the latest development version. In the meanwhile, if you sudo apt-get install netcat-openbsd and then try again it should work.