How does TLS-RPT work with MTA-STS?
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But Here's the thing: you can't safely enforce MTA-STS without knowing what's actually failing. That's where TLS-RPT comes in. These two standards work together like a safety net and the alarm system that tells you it's catching something.
MTA-STS is your enforcement policy. It says "accept only encrypted connections to my mail servers." But if you turn enforcement on without knowing what'll break, you might block legitimate mail. That's why you start in testing mode first. TLS-RPT is what watches that testing phase and reports back to you.
And Here's the workflow. You publish your MTA-STS policy in testing mode, then you set up TLS-RPT reporting (it's just a DNS record pointing to an email address like tlsrpt@yourdomain.com). When other mail servers try to connect and hit problems. TLS-RPT logs that failure. Maybe a certificate expired, maybe the server doesn't support TLS. The reports show you exactly what went wrong.
After a few weeks of monitoring those reports and fixing the issues they surface, you're ready. You switch MTA-STS to enforce mode, knowing you've already caught and resolved the major problems. That's the partnership: MTA-STS enforces security, TLS-RPT tells you what needs fixing first.
Start by checking what MTA-STS policy modes actually do, then learn how to set up your TLS-RPT reporting endpoint.
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