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SMTP connection BBC/BCC RRS feed

  • Question

  • Hello

    how many connections is opened when sending 100 mails? And 1000? When does the connection close?
    Let's suppose 100 emails are sent with BBC/BCC and 50 recipients use the same ISP, as they are individually sent, do we open 100 connections?

    We encounter the issue 

    mta-gw.infomaniak.ch Remote Server returned '554 5.4.0 <mta-gw.infomaniak.ch #4.3.2 smtp; 421 4.3.2 Connection rate limit exceeded.>'

    mta-gw.infomaniak.ch Remote Server returned '554 5.4.0 <mta-gw.infomaniak.ch #4.3.2 smtp; 421 4.3.2 Too many open connections.>'

    I am not able to read the SMTP RFC, could someone help me to understand how connection are opened and closed when sending emails? 

    Any help is much appreciated,

    Yann

    Thursday, February 8, 2018 2:29 PM

Answers

  • Thanks for your response.

    I cannot found any documents about this, per my experience and the Protocol log, it should be one connection one mail since one connection is droped with the mail end command ".".

    Thanks.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


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    • Edited by Jason.Chao Tuesday, February 20, 2018 8:39 AM
    • Proposed as answer by Jason.Chao Tuesday, February 20, 2018 8:39 AM
    • Unproposed as answer by Jason.Chao Thursday, March 15, 2018 8:58 AM
    • Proposed as answer by Jason.Chao Thursday, March 15, 2018 8:58 AM
    • Marked as answer by Sayannara Thursday, June 21, 2018 6:37 AM
    Tuesday, February 20, 2018 8:38 AM

All replies

  • Hello Yann,

    Thanks for contacting our forum. We can add the max inbound connection per source with the command below:

    Set-receiveconnector - identity "connector name" -MaxInboundconnectionPersource 300

    Please refer to: https://technet.microsoft.com/en-us/library/bb232205%28v=exchg.160%29.aspx?f=255&MSPPError=-2147217396

    Hope it helps.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    • Proposed as answer by Allen_WangJF Thursday, February 15, 2018 1:48 PM
    • Unproposed as answer by Jason.Chao Thursday, March 15, 2018 8:58 AM
    Friday, February 9, 2018 3:08 AM
  • Hello

    actually we do have an appliance "Clearswift" which is our gateway, so no need for me to limit the connection rate on the Exchange server. I needed to know how many emails can be sent with one connection.

    Apparantly one connection is opened for each email sent. Could you confirm this information?

    Thank you,

    Yann


    • Edited by Sayannara Friday, February 16, 2018 1:15 PM orth
    Friday, February 16, 2018 8:09 AM
  • Thanks for your response.

    I cannot found any documents about this, per my experience and the Protocol log, it should be one connection one mail since one connection is droped with the mail end command ".".

    Thanks.


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.
    • Edited by Jason.Chao Tuesday, February 20, 2018 8:39 AM
    • Proposed as answer by Jason.Chao Tuesday, February 20, 2018 8:39 AM
    • Unproposed as answer by Jason.Chao Thursday, March 15, 2018 8:58 AM
    • Proposed as answer by Jason.Chao Thursday, March 15, 2018 8:58 AM
    • Marked as answer by Sayannara Thursday, June 21, 2018 6:37 AM
    Tuesday, February 20, 2018 8:38 AM
  • Hi,
     
    We are currently standing by for further update from you and would like to know how things are going. If you have any questions or concerns, please don't hesitate to let me know. And if the replies has helped you, please help to mark as answer since it could be helpful for others.
     
    Thanks for your time.

    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    • Proposed as answer by Jason.Chao Wednesday, March 7, 2018 2:18 AM
    Tuesday, March 6, 2018 9:49 AM
  • Any updates? or if you've resolved this issue, could you please share out and mark as answer, since it will be helpful for others.

    Thanks for your kindly understanding!


    Best Regards,
    Jason Chao


    Please remember to mark the replies as answers if they helped. If you have feedback for TechNet Subscriber Support, contact tnsf@microsoft.com.


    Click here to learn more. Visit the dedicated forum to share, explore and talk to experts about Microsoft Teams.

    Thursday, March 15, 2018 10:08 AM
  • Hello

    I'm really sorry for the delay.

    I finaly limitted the connection in both of our gateways. That is correct one connection for one email.

    We still have an issue when sending more than 200 emails in a time to a specific provider.

    Thursday, June 21, 2018 6:35 AM