Exchange 2013 CU23 unable to receive external emails

Question

Hi

Exchange 2013 CU23.
There is no mails in Queue Viewer.
I can send out email but unable to receive emails.
External party received "Delivery Incomplete" after sent email to me.
Error message is " The recipient server did not accept our requests to connect. Learn more https://support.google.com/mail/answer/7720 <ourmail.server.com> <our ip address> : timed out"

Answer 1

I did Inbound SMTP test of https://testconnectivity.microsoft.com/.
Connectivity Test Failed.
Attempting to send a test email message to mine@keyman .com using MX <mymail.domain.com>
Delivery of the test email message failed.

Additional Details
The server returned status code 530 - The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Client was not authenticated

Exception details:

Message: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Client was not authenticated

Type: System.Net.Mail.SmtpException

Stack trace:

at System.Net.Mail.MailCommand.CheckResponse(SmtpStatusCode statusCode, String response)

at System.Net.Mail.MailCommand.Send(SmtpConnection conn, Byte[] command, MailAddress from, Boolean allowUnicode)

at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception)

at System.Net.Mail.SmtpClient.Send(MailMessage message)

at Microsoft.M365.RCA.ConnectivityTests.SmtpMessageTest.PerformSmtpMessageTest(RcaTestContext parent, String mailExchangerHost, ISmtpAddress emailAddress, ContextInfo contextInfo, SmtpOptions smtpOptions)

Answer 2

Is it safe to add Anonymous users in Permission Groups?
Please refer to:
https://social.technet.microsoft.com/Forums/ie/en-US/3201f365-5b74-438f-b431-f8dc194958cc/571-client-was-not-authenticated?forum=exchange2010

Answer 3

I did Inbound SMTP test of https://testconnectivity.microsoft.com/.
Connectivity Test Failed.
Attempting to send a test email message to mine@keyman .com using MX <mymail.domain.com>.
Delivery of the test email message failed.

The server returned status code -1 - Failure sending mail.

Exception details:

Message: Failure sending mail.

Type: System.Net.Mail.SmtpException

Stack trace:

at System.Net.Mail.SmtpClient.Send(MailMessage message)

at Microsoft.M365.RCA.ConnectivityTests.SmtpMessageTest.PerformSmtpMessageTest(RcaTestContext parent, String mailExchangerHost, ISmtpAddress emailAddress, ContextInfo contextInfo, SmtpOptions smtpOptions)

Exception details:

Message: Unable to connect to the remote server

Type: System.Net.WebException

Stack trace:

at System.Net.ServicePoint.GetConnection(PooledStream PooledStream, Object owner, Boolean async, IPAddress& address, Socket& abortSocket, Socket& abortSocket6)

at System.Net.PooledStream.Activate(Object owningObject, Boolean async, GeneralAsyncDelegate asyncCallback)

at System.Net.ConnectionPool.GetConnection(Object owningObject, GeneralAsyncDelegate asyncCallback, Int32 creationTimeout)

at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)

at System.Net.Mail.SmtpClient.GetConnection()

at System.Net.Mail.SmtpClient.Send(MailMessage message)

Exception details:

Message: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond <IP address>:25

Type: System.Net.Sockets.SocketException

Stack trace:

at System.Net.Sockets.Socket.DoConnect(EndPoint endPointSnapshot, SocketAddress socketAddress)

at System.Net.ServicePoint.ConnectSocketInternal(Boolean connectFailure, Socket s4, Socket s6, Socket& socket, IPAddress& address, ConnectSocketState state, IAsyncResult asyncResult, Exception& exception)

Answer 4

Hi @Phua Kwang Hwee

Please refer to the introduction in the official document: DSNs and NDRs in Exchange 2013

If you disable anonymous then your mail server won't receive email from the internet. Mails from the internet are not part of your domain, it can't be authenticated against AD. So there for it is anonymous.

And a similar thread here discussed the similar question, you could take a reference as well:
inbound mail rejecting - Client was not authenticated

Get-ReceiveConnector <servername\Default Frontend servername>| Format-List Identity,Bindings,PermissionGroups   
Set-ReceiveConnector <servername\Default Frontend servername> -PermissionGroups AnonymousUsers, ExchangeServers, ExchangeLegacyServers  

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