451 4.4.0 Primary target IP address responded with: “421 4.2.1 Unable to connect.” Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts.

Hello, 

I have problem with new installed Exchange 2013 Server, I can receive mails from outside organization, but can not send mails on gmail.com yahoo.com hotmail.com, outlook.com and etc.

mails are in queue list with error :

451 4.4.0 Primary target IP address responded with: “421 4.2.1 Unable to connect.” Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts.