Exchange Server 2019 stopped sending outgoing e-mail RRS feed

  • Question

  • So out of the blue an Exchange Server 2019 unit, with one e-mail policy on it, stopped sending e-mail.

    I've reconfigured, removed and rebuilt the send connector for e-mail, and it won't send anything.

    We tried forwarding through a smart host with multiple configurations on the send connector, and still nothing.

    We were restarting services after configuration changes just in case that was necessary, and still nothing.

    On a side note, the issue began when the domain name on the server was blacklisted for about couple of days last week, but that didn't stop the server from at least trying to send e-mail.  As of now, it wont' send anything (even though the mail flow reports say that mail is being handed off to outside organizations - but no one gets anything, at any external address).

    What is something I can check that would help me understand the problem, and how do I check it?

    Thank you, before hand.

    Alert from Microsoft Forum

    Tuesday, September 17, 2019 3:30 AM

All replies

  • Hi

    Did you check to make sure it is still not listed anywhere? some places will only remove the listing once the spam etc. stops from that IP. 

    Maybe you are still listed or the IP has been hijacked and used as an open relay. please check.

    Hope this helps. Please remember to click “Mark as Answer” on the post that helps you, and to click “Unmark as Answer” if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

    Tuesday, September 17, 2019 5:23 AM
  • Yes, I hit mxtoolbox, spamhaus, etc, to verify the name and IP.

    Its not an IP issue.

    We've change the send connector to route mail through a smarthost.

    That doesn't work either.  We can't send mail, and can't find anything wrong, so any help would be appreciated.

    Alert from Microsoft Forum

    • Edited by DarkAngel11 Tuesday, September 17, 2019 2:40 PM
    Tuesday, September 17, 2019 12:03 PM
  • Hi,

    What's the result of running get-messagetrackinglog?

    Try enabling the protocol logging on your send connector. The protocol log will show the SMTP conversation between your server and the external recipient's server, so any SMTP errors should appear in the log.

    Set-SendConnector "name" -ProtocolLoggingLevel Verbose

    For more detailed information, you can refer to the following article:

    Outbound Mail Flow for Exchange Server 2016

    Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.


    Joyce Shen

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

    Wednesday, September 18, 2019 3:21 AM
  • Hi DarkAngel11,

    Do suggestions above help? If you have any questions or needed further help on this issue, please feel free to post back. If the issue has been resolved, please mark the helpful replies as answers, this will make answer searching in the forum easier and be beneficial to other community members as well.

    Thanks for your understanding.


    Joyce Shen

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

    Friday, September 20, 2019 9:25 AM