Exchange 2007 421 4.3.2 Service not available, closing transmission channel


Just switch ISP and having issues with mail flow with exchange 2007
when sending an email to the domain I receive a Email Delivery Warning 4.3.2 Service not available, closing transmission channel

Ben SAsked:
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Valentina PerezExchange ServersCommented:
Hi Ben,

You need to check if you have backpressure. Do you have any events between 15000-15010?

Zaheer IqbalTechnical Assurance & ImplementationCommented:
is this issues with outgoing mails or incoming or both ?
Ben SAuthor Commented:

No events in the events viewer between 15000-15010.
outgoing is working but taking longer than normal to receive, around 15 minutes.

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Ben SAuthor Commented:
from the Microsoft connection test

The Microsoft Connectivity Analyzer failed to test inbound SMTP mail flow.
	Additional Details
Elapsed Time: 584 ms.
	Test Steps
	Attempting to retrieve DNS MX records for domain ''.
 	One or more MX records were successfully retrieved from DNS.
	Additional Details
MX Records Host, Preference 5
Elapsed Time: 16 ms.
	Testing Mail Exchanger
 	One or more SMTP tests failed for this Mail Exchanger.
	Additional Details
Elapsed Time: 567 ms.
	Test Steps
	Attempting to resolve the host name in DNS.
 	The host name resolved successfully.
	Additional Details
IP addresses returned: 
Elapsed Time: 353 ms.
	Testing TCP port 25 on host to ensure it's listening and open.
 	The port was opened successfully.
	Additional Details
Banner received: 421 4.3.2 Service not available, closing transmission channel
Elapsed Time: 140 ms.
	Analyzing SMTP Capabilities for server
 	The test passed with some warnings encountered. Please expand the additional details.
	Additional Details
Unabled to determine SMTP capabilities. Reason: Unexpected SMTP server response. Expected: 220, actual: 421, whole response: 421 4.3.2 Service not available, closing transmission channel
Elapsed Time: 38 ms.
	Attempting to send a test email message to using MX
 	Delivery of the test email message failed.
	Additional Details
The server returned status code 421 - Service not available, closing transmission channel. The server response was: 4.3.2 Service not available, closing transmission channel
Exception details:
Message: Service not available, closing transmission channel. The server response was: 4.3.2 Service not available, closing transmission channel
Type: System.Net.Mail.SmtpException
Stack trace:
at System.Net.Mail.SmtpConnection.GetConnection(ServicePoint servicePoint)
at System.Net.Mail.SmtpClient.Send(MailMessage message)
at Microsoft.Exchange.Tools.ExRca.Tests.SmtpMessageTest.PerformTestReally()
Elapsed Time: 36 ms.

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Zaheer IqbalTechnical Assurance & ImplementationCommented:
Not sure of your configuration and setup please check your receive connectors on the CAS.
Zaheer IqbalTechnical Assurance & ImplementationCommented:
Have you updated your MX record to new ISP IP.
Ben SAuthor Commented:
I have updated the mx record with DNS provided and added the new IP to the receive connector remote IP, is this correct?
Zaheer IqbalTechnical Assurance & ImplementationCommented:
Try and see what that comes back does it come back with the correct IP ?
Zaheer IqbalTechnical Assurance & ImplementationCommented:
Has a reverse DNS record been setup for your mail by the new ISP ?

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Ben SAuthor Commented:
Just figured out the issue thanks for the help,

I just added  to the internet receive connector
Ben SAuthor Commented:
should this be or just the public IP of the exchange server?
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