For each outside email I have the same error:
12:28:03  Failed to connect to the recipients mail server. No MX records were found for the 'gmail.com' domain. Failing over to A records.
12:28:03  Initiating connection to 184.108.40.206
12:28:03  Connecting to 220.127.116.11:25 (Id: 1)
12:28:24  Exception connecting to 18.104.22.168 (Id: 1)
12:28:24  System.Net.Sockets.SocketException (0x80004005): An attempt was made to access a socket in a way forbidden by its access permissions 22.214.171.124:25
at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)
at System.Net.Sockets.Socket.Connect(EndPoint remoteEP)
at RelayServer.Clients.SMTP.ClientConnectionSync.Connect(Int32 connectionId)
12:28:24  Connection to 126.96.36.199 failed (Id: 1)
Can anybody help me or suggest anything forward ?
Even I pointed on Google DNS so for sure DNS is not the reason.