we are using exchange server 2013 and our exchange server receive and send email properly on local network, and receiving incoming emails from outside network but Outgoing e-mails stuck in queue with error {LED=441 4.4.1 error encountered while communicating with primary target IP Address:"421 4.4.2 connection dropped due to SocketError." attempted failover to alternate host, but that did not succeed. Either there are no alternate host.
Also created new send connector and did telnet to port 25 and uninstall Antivirus as well.