EXCHANGE   Exchange – 421 4.4.2 Message submission rate for this client has exceeded the configured limit



An application started to log random error messages when trying to send emails through one of my Exchange receive connectors. So I checked and filtered the "Client Frontend" receive connector that showed at certain minute 6 email deliveries.

2016-01-12T17:49:00.530Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E90,3,10.20.20.5:587,10.10.6.10:59301,<,EHLO server1,
2016-01-12T17:49:00.811Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E90,43,10.20.20.5:587,10.10.6.10:59301,*,,Proxy session was successfully set up. Session for application1 will now be proxied

2016-01-12T17:49:01.155Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E92,3,10.20.20.5:587,10.10.6.10:59302,<,EHLO server1,
2016-01-12T17:49:01.421Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E92,43,10.20.20.5:587,10.10.6.10:59302,*,,Proxy session was successfully set up. Session for application1 will now be proxied

2016-01-12T17:49:01.764Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E94,3,10.20.20.5:587,10.10.6.10:59303,<,EHLO server1,
2016-01-12T17:49:02.014Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E94,43,10.20.20.5:587,10.10.6.10:59303,*,,Proxy session was successfully set up. Session for application1 will now be proxied

2016-01-12T17:49:02.343Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E97,3,10.20.20.5:587,10.10.6.10:59304,<,EHLO server1,
2016-01-12T17:49:02.593Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E97,43,10.20.20.5:587,10.10.6.10:59304,*,,Proxy session was successfully set up. Session for application1 will now be proxied

2016-01-12T17:49:02.921Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E99,3,10.20.20.5:587,10.10.6.10:59305,<,EHLO server1,
2016-01-12T17:49:03.171Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E99,43,10.20.20.5:587,10.10.6.10:59305,*,,Proxy session was successfully set up. Session for application1 will now be proxied

2016-01-12T17:49:03.499Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E9B,3,10.20.20.5:587,10.10.6.10:59306,<,EHLO server1,
2016-01-12T17:49:03.749Z,EXCHANGESRV\Client Frontend EXCHANGESRV,08D31A7027871E9B,43,10.20.20.5:587,10.10.6.10:59306,*,,Proxy session was successfully set up. Session for application1 will now be proxied

Then I checked and filtered my Exchange "Client Proxy" receive connector that showed 5 email deliveries and 1 error message:

2016-01-12T17:49:00.905Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87A7,66,10.20.20.5:465,10.20.20.5:61643,*,,receiving message with InternetMessageId <892486179.161.1452620940960.JavaMail.tomcat@application1>
2016-01-12T17:49:01.014Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87A7,67,10.20.20.5:465,10.20.20.5:61643,>,"250 2.6.0 <892486179.161.1452620940960.JavaMail.tomcat@application1> [InternalId=27504970564284, Hostname=EXCHANGESRV.bilbokoudala.lan] Queued mail for delivery",

2016-01-12T17:49:01.499Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87AB,66,10.20.20.5:465,10.20.20.5:61649,*,,receiving message with InternetMessageId <1648812533.164.1452620941562.JavaMail.tomcat@application1>
2016-01-12T17:49:01.624Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87AB,67,10.20.20.5:465,10.20.20.5:61649,>,"250 2.6.0 <1648812533.164.1452620941562.JavaMail.tomcat@application1> [InternalId=27504970564286, Hostname=EXCHANGESRV.bilbokoudala.lan] Queued mail for delivery",

2016-01-12T17:49:02.108Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87AE,66,10.20.20.5:465,10.20.20.5:61658,*,,receiving message with InternetMessageId <238445017.167.1452620942165.JavaMail.tomcat@application1>
2016-01-12T17:49:02.218Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87AE,67,10.20.20.5:465,10.20.20.5:61658,>,"250 2.6.0 <238445017.167.1452620942165.JavaMail.tomcat@application1> [InternalId=27504970564287, Hostname=EXCHANGESRV.bilbokoudala.lan] Queued mail for delivery",

2016-01-12T17:49:02.686Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87B1,66,10.20.20.5:465,10.20.20.5:61677,*,,receiving message with InternetMessageId <81067270.170.1452620942738.JavaMail.tomcat@application1>
2016-01-12T17:49:02.796Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87B1,67,10.20.20.5:465,10.20.20.5:61677,>,"250 2.6.0 <81067270.170.1452620942738.JavaMail.tomcat@application1> [InternalId=27504970564288, Hostname=EXCHANGESRV.bilbokoudala.lan] Queued mail for delivery",

2016-01-12T17:49:03.249Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87B4,66,10.20.20.5:465,10.20.20.5:61690,*,,receiving message with InternetMessageId <635306337.173.1452620943315.JavaMail.tomcat@application1>
2016-01-12T17:49:03.374Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87B4,67,10.20.20.5:465,10.20.20.5:61690,>,"250 2.6.0 <635306337.173.1452620943315.JavaMail.tomcat@application1> [InternalId=27504970564289, Hostname=EXCHANGESRV.bilbokoudala.lan] Queued mail for delivery",

2016-01-12T17:49:03.780Z,EXCHANGESRV\Client Proxy EXCHANGESRV,08D31A704B0F87B7,59,10.20.20.5:465,10.20.20.5:61698,>,421 4.4.2 Message submission rate for this client has exceeded the configured limit,

That error message was appearing everytime this application started sending multiple mails.
The problem was on the receive connector MessageRateLimit default value parameter.
There is a limitation of a number of messages that can be sent through the receive connector per minute:

[PS] C:\>Get-ReceiveConnector "EXCHANGESRV\Client Proxy EXCHANGESRV" | fl Name,MessageRateLimit

Name             : Client Proxy EXCHANGESRV
MessageRateLimit : 5

To change the parameter:

[PS] C:\>Get-ReceiveConnector "EXCHANGESRV\Client Proxy EXCHANGESRV" | Set-ReceiveConnector -MessageRateLimit 30

[PS] C:\>Get-ReceiveConnector "EXCHANGESRV\Client Proxy EXCHANGESRV" | fl Name,MessageRateLimit

Name             : Client Proxy EXCHANGESRV
MessageRateLimit : 30

And the problem is solved ๐Ÿ™‚

5 thoughts on “Exchange – 421 4.4.2 Message submission rate for this client has exceeded the configured limit

  1. Yep , nice. We had some similar issues in our Exchange 2010 and Exchange 2016 Multi Tenant environments. Since the solution via ReceiveConnector affects all mailboxes, we solved it via Throttling Policy on mailbox level.

  2. Hi! Could you give tip, where to look for Client Proxy logs? I turn on logging for this Receive Connector with Powershell and set value to Verbose, but in logfiles in Program Files\Microsoft\Exchange Server\V15\TransportRoles\Logs\FrontEnd\ProtocolLog\SmtpReceive folder there is not such info as in your example. I have only records from Client Frontend SERVERNAME (port 587) and Default Frontend SERVERNAME (port 25) connectors, but not proxied connections on port 465.

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