public static boolean isEnabled() {
        return JiveGlobals.getBooleanProperty(ConnectionSettings.Server.DIALBACK_ENABLED, true);
    }
Returns true if server dialback is enabled. When enabled remote servers may connect to this
server using the server dialback method and this server may try the server dialback method
to connect to remote servers.<p>

When TLS is enabled between servers and server dialback method is enabled then TLS is going
to be tried first, when connecting to a remote server, and if TLS fails then server dialback
is going to be used as a last resort. If enabled and the remote server offered server-dialback
after TLS and no SASL EXTERNAL then server dialback will be used.

@return true if server dialback is enabled.
xmppserver/src/main/java/org/jivesoftware/openfire/server/ServerDialback.java