SMTP Error on new chatmail relay

I installed a new chatmail relay server, and installation finished without any problem.
But when I want to create a new account on it I get this error:

SMTP failed to connect: All connection attempts failed: Connection to xx.xx.xx.xx failed: No connection could be made because the target machine actively refused it. (os error 10061)

Postfix service is started correctly, too.

what should I do at this point?

The problem has solved after re-installation.