Poor IP Reputation in Exchange Server 2013 RRS feed

  • Question

  • Hello,

    We are using Exchange Server 2013 on Windows Server 2012 R2 and we are facing poor IP reputation issue for the last three days and due to this few of our users are getting bounced back emails stating

     451 4.4.0 554 Your access to this mail system has been rejected due to the sending MTA's poor reputation. If you believe that this failure is in error, please contact the intended recipient via alternate means.." Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts.

    Our IP Address is not in blacklist or poor reputation in  https://mxtoolbox.com, https://www.dnsbl.info, https://whatismyipaddress.com/blacklist-check, http://multirbl.valli.org/ but its showing poor IP reputation in https://www.talosintelligence.com/

    Our Reserve DNS, PTR, SPF, HELO FQDN everything is working fine.

    Kindly provide some suggestion.



    Thursday, September 27, 2018 7:27 AM

All replies

  • hi,

    can you check your mail stats to see if problematical user is sending high volume mail.  One of the most common sources of spam are phished passwords on email accounts used until someone catches on or an insecure/folder script on the server if you are using web/email on the same server. 
    can you change email password for users who getting bounced back emails and look if the problem persist for that user?

    If the problem persist, you need to paste your problem to exchange forum for more professional support.


    you can refer these documents :

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

    Friday, September 28, 2018 10:47 AM
  • Hello,

    We opened the case with Cisco Talos and after 2 days they clear our IP from poor reputation.



    Tuesday, October 23, 2018 11:28 AM