Unexpected SMTP server response. Expected: 220, actual: 500
Posted on 2013-07-01
Exchange 2012 version 15.0 on server 2012
Getting the following error message when i run the Remote connectivity Analyzer. I have made adjustments to the auth mechanisms but have not been able to resolve the issue.
Also, every once in a while, I get the 451 local error. I immediately rerun the test and everything works. I mention this because there are times that email gets rejected with "#5.4.4 smtp;554 5.4.4 SMTPSEND.DNS.NonExistentDomain; nonexistent domain". It is unpattered and happens a few times during the day.
Testing inbound SMTP mail flow for domain ME@Mycomp.com
Inbound SMTP mail flow was verified successfully.
Attempting to retrieve DNS MX records for domain Mycomp.com.
One or more MX records were successfully retrieved from DNS.
MX Records Host server.mycomp.com, Preference 10
Testing Mail Exchanger server.mycomp.com.
This Mail Exchanger was tested successfully.
Attempting to resolve the host name server.mycomp.com in DNS.
The host name resolved successfully.
IP addresses returned: XX.XX.XX.XX
Testing TCP port 25 on host server.mycomp.com to ensure it's listening and open.
The port was opened successfully.
Banner received: 220 server.mycomp.com Microsoft ESMTP MAIL Service ready at Mon, 1 Jul 2013 12:50:25 -0500
Analyzing SMTP Capabilities for server server.mycomp.com:25
The test passed with some warnings encountered. Please expand the additional details.
Unabled to determine SMTP capabilities. Reason: Unexpected SMTP server response. Expected: 220, actual: 500, whole response: 500 5.3.3 Unrecognized command
Attempting to send a test email message to firstname.lastname@example.org using MX server.mycomp.com.
The test email message was delivered successfully.
Testing the MX server.mycomp.com for open relay by trying to relay to user Admin@TestExchangeConnectivity.com.
The Open Relay test passed. This MX isn't an open relay.
The open relay test message delivery failed, which is a good thing.
The exception detail:
Message: Mailbox unavailable. The server response was: 5.7.1 Unable to relay
at System.Net.Mail.SmtpTransport.SendMail(MailAddress sender, MailAddressCollection recipients, String deliveryNotify, Boolean allowUnicode, SmtpFailedRecipientException& exception)
at System.Net.Mail.SmtpClient.Send(MailMessage message)
Thanks a bunch in advance