Trend Micro - Securing Your Journey to the Cloud Business
Support
Sign In with your
Trend Micro Account
Need Help?
Need More Help?

Create a technical support case if you need further support.

"554 Service unavailable" error message appears when sending emails in Hosted Email Security (HES)

    • Updated:
    • 13 Mar 2018
    • Product/Version:
    • Hosted Email Security 2.0
    • Platform:
    • N/A N/A
Summary

You cannot send an email to some HES recipients. You receive the following non-delivery receipt (NDR) message:

554 Service unavailable; Client host [xx.xx.xx.xx] blocked using ips.backscatterer.org; Sorry xx.xx.xx.xx is blacklisted at http://www.backscatterer.org/?ip=xx.xx.xx.xx (in reply to RCPT TO command))

The NDR message shows that the recipient is using Backscatterer, which is blocking the HES outbound IP address.

Details
Public

Backscatterer is not the actual cause of the issue. The issue happens because the service is not being used correctly.

Backscatterer is not a blacklist or a spammerlist. It is a sender callout abuser (Ex: misdirected auto responders) list. Backscatterer recommends that you use the ips.backscatterer.org list in Safe Mode.

Emails should not be blocked based solely on this list instead the list should be used by mail server administrators to determine or tag possible spam. When solely relied upon, Backscatterer will block legitimate emails from different sources.

If this is happening to you, contact the intended email recipient and advise them to use Backscatterer in Safe Mode.

Premium
Internal
Rating:
Category:
Troubleshoot
Solution Id:
1060323
Feedback
Did this article help you?

Thank you for your feedback!

To help us improve the quality of this article, please leave your email here so we can clarify further your feedback, if neccessary:
We will not send you spam or share your email address.

*This form is automated system. General questions, technical, sales, and product-related issues submitted through this form will not be answered.

If you need additional help, you may try to contact the support team. Contact Support

To help us improve the quality of this article, please leave your email here so we can clarify further your feedback, if neccessary:
We will not send you spam or share your email address.

*This form is automated system. General questions, technical, sales, and product-related issues submitted through this form will not be answered.
Related Articles