What is TLS-RPT?
TLS-RPT (SMTP TLS Reporting) is an email security standard that gives you a clear view of how securely email is being delivered to your domain, and flags up any transport problems along the way.
It lets you receive reports about any trouble other mail servers run into when they try to send encrypted email to your domain.
Where SPF, DKIM, and DMARC focus on checking that an email really comes from who it claims to, TLS-RPT focuses on keeping an eye on the security and reliability of encrypted email delivery.
Why is TLS-RPT Important?
Email systems increasingly rely on encrypted connections to keep messages protected while they travel across the internet.
Encryption can run into trouble for all sorts of reasons, including:
- Mail servers that are not set up correctly
- Expired security certificates
- DNS problems
- Issues at a third-party provider
- Conflicting transport security policies
Without a way to see these issues, you might not realise that encrypted email delivery is failing or being held back.
TLS-RPT helps you spot these problems by collecting reports from email providers and mail systems that take part.
What Does TLS-RPT Report On?
TLS-RPT reports can give you insight into situations where:
- Encrypted email delivery could not be set up.
- Security policies could not be checked.
- A security certificate could not be verified.
- Mail servers could not meet the required transport security.
- Email was delayed or turned away because of transport security issues.
This helps you understand how your email setup is performing from the point of view of the people sending to you.
Why Visibility Matters
Many email transport security problems happen quietly, with no obvious sign that anything is wrong.
Messages might still get through, or be delayed, retried, or turned away, all without anyone noticing straight away that there is a problem.
TLS-RPT helps you see what is really going on, including:
- Transport security failures
- Configuration issues
- Problems that are just starting to appear
- Trends and issues that keep coming back
- How well your email security is actually working
Without these reports, problems like these can be very hard to find.
TLS-RPT and MTA-STS
TLS-RPT is often used hand in hand with MTA-STS.
The two work together:
- MTA-STS helps set out your transport security requirements.
- TLS-RPT tells you how those requirements are holding up in the real world.
A handy way to think about them is:
- MTA-STS sets the rules.
- TLS-RPT tells you what happens when those rules are put into practice.
Together they help you make your email transport more secure and more reliable.
Benefits of TLS-RPT
With TLS-RPT you can:
- See clearly how secure your email transport is.
- Spot delivery problems affecting encrypted email.
- Catch configuration mistakes.
- Keep an eye on how well your transport security policies are working.
- Build more reliable and trusted email.
- Stay one step ahead with your email security.
Why Monitoring Matters
TLS-RPT reports can hold a lot of technical detail, sent in by email providers from all around the world.
As your email setup changes over time, new issues can crop up because of things like:
- Changes to your infrastructure
- DNS updates
- Certificate renewals
- Moving to new mail servers
- Changes made by third-party services
Keeping an eye on things regularly helps you catch and fix problems before they affect your business communications.
TLS-RPT as Part of a Security Strategy
TLS-RPT does not stop phishing, spoofing, or email impersonation on its own.
What it does is give you a valuable view into the health and security of your email transport, so you can tell whether everything is working as it should.
Used alongside SPF, DKIM, DMARC, and MTA-STS, TLS-RPT rounds out a complete email security approach that builds trust, security, and reliability.