This error (per RFC 8461 Section 3.3) indicates we were unable to find or connect to the MTA-STS Policy for the domain provided. This test attempts to establish a connection to the MTA-STS Policy. This policy is required to be hosted as a text file on a subdomain with the standard format of mta-sts.domain.com. With that format, your domain would replace the domain.com part of the subdomain.
How can I resolve this issue?
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Set up an MTA-STS Policy by creating a subdomain in the format of mta-sts.domain.com
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If you have already setup the page and are getting the error, verify:
1. The page uses HTTPS by default, as HTTP will be treated as invalid
2. Verify you are not blocking traffic to that subdomain or that you have a misconfiguration on the page
Your Email Deliverability is in Jeopardy!
Blacklisting is a sign that you are not actively managing your email deliverability. Other technologies - SPF, DKIM and DMARC are now just as important to get your email placed in the Inbox of your recipients. If you aren’t managing email deliverability, your message may never be heard.
MxToolbox Delivery Center Features:
- Insight into your SPF, DKIM and DMARC configuration to ensure your sending email properly
- DMARC Compliance checks for all of your reported email
- Adaptive Blacklist Monitoring of all your email senders
- Recommendations for improving DMARC compliance and DMARC policies
- Event-based reminders for emergent issues and on-going maintenance
DMARC is a necessity for your business!
Learn More about Email Delivery