TLS-RPT: Get Alerts When Email Encryption Fails

What Is TLS-RPT

You email a client a contract. Their server connects to your mail server to deliver it. That connection is supposed to be encrypted, like a sealed, locked package. But what if the lock breaks—or was never even there? Without a way to hear about it, you’d have no idea a sensitive message traveled in the open.

TLS-RPT (Transport Layer Security Reporting) closes that gap. It’s a tiny instruction you add to your domain’s public directory (called DNS) that asks any mail server who tries to talk to yours: “If the encryption handshake fails, send me a report.” No report means everything’s fine; a report means you have a problem you couldn’t see before.

Real-World Analogy

Picture a hotel. Room key cards sometimes fail to program. The hotel sets up a system where every key machine that can’t encode a card emails the front desk automatically. Now the manager knows exactly which machine is glitchy and can fix it before guests get locked out. TLS-RPT is that system for your email server’s encryption handshakes—silent, automatic, and far more useful than guessing.

How TLS-RPT Works

Plain‑English walkthrough: When another company’s mail server tries to deliver a message to your inbox, it first attempts to create an encrypted tunnel—like dialing a scrambled phone line. If that fails (maybe your server’s certificate expired, or it only offers an outdated cipher), the sending server normally has two choices: switch to an unencrypted connection and deliver anyway, or bounce the message. You’d never know which one happened.

With TLS-RPT, you’ve posted a notice in DNS that says: “Please, if you ever hit a snag during encryption, send a summary report to reports@mycompany.com.” The sending server looks up that notice, follows the instructions, and once a day emails you a compact report. The report lists how many connections succeeded, how many failed, and the reasons why. Suddenly you can spot that 3% of connections from one geography are failing—and you know exactly what to fix.

Technical Details

▸The notice lives at as a TXT record.

▸Record value example:

▸ lists URIs where aggregate reports should go. is most common, but endpoints are also supported.

▸Reports arrive as GZIP-compressed JSON files, typically every 24 hours. They summarize both successful and failed TLS negotiations—not individual messages, so no private content is leaked.

▸Common failure reasons include expired certificates, no shared cipher suites, or a DNS misdirection.

Why It Matters for Your Business

When encryption breaks, so does trust. If customers, partners, or your own team can’t send email securely, sensitive data might travel in plain text. In regulated industries—law, finance, healthcare—that’s not just embarrassing; it can violate compliance rules. TLS-RPT makes sure you’re the first to know, not the last.

It’s also a deliverability guardian. Some sending servers will refuse to talk to a domain that can’t maintain proper encryption, sending your legitimate email to spam or rejecting it outright. A spike in failures on your report is an early warning that your reputation could be about to take a hit and that you need to call your email provider before it impacts real conversations.

This matters beyond IT. Sales teams lose deals when proposals land in spam. Customer support gets blamed when reset links never arrive. Your executive team’s confidential discussions could be exposed. TLS-RPT safeguards everyone who relies on email—and the easiest way to get started is a five‑minute DNS update.

Common Issues and Warning Signs

You might add the record and hear nothing for weeks. That could mean everything is perfect—or it could mean the record never took effect, or the address you entered can’t receive reports. Without a quick check, you’re still operating blind.

Common Issues

You’re not receiving any reports. Check that the address is correct and not blocked by spam filters. Also make sure the record was saved under the exact name (a common mistake is using by accident).

Your report shows a sudden jump in “certificate‑expired” failures. That usually means the TLS certificate on your mail server has lapsed. Even if your email still flows, it’s flowing without encryption until it’s renewed.

A large percentage of incoming connections fall back to plain text. This hints that your server might support only outdated protocols, or that opportunistic encryption is failing silently. It’s a red flag worth investigating.

You see failures from a specific sender’s IP range. It could be a compatibility glitch between your email security platform and theirs—TLS-RPT gives you the precise data to forward to your IT team or provider support.

How to Fix or Improve TLS-RPT

Most of the time, the only thing missing is the DNS record. If you have access to your domain’s DNS panel (wherever you bought your domain or where your nameservers point), you can add it yourself. If someone else manages DNS for you, just forward them the steps.

Once reports start flowing, even a quick glance once a week can save you from a world of encrypted mishaps. Run a TechSpy scan on your domain; we’ll instantly tell you if TLS-RPT is already in place or point out exactly what’s missing.

1Log into your DNS provider’s control panel (e.g., GoDaddy, Cloudflare, Namecheap, or wherever your domain’s nameservers are hosted).

2Create a new TXT record with the hostname (so the full name becomes ).

3Set the value to — replace the email address with one your team monitors. You can add a second address separated by a comma if needed.

4Save the record and wait up to an hour for it to propagate. Then test it using a free tool like MXToolbox’s TLS-RPT lookup, or simply send an email from an external account and check a day later for a report.

5If you use Google Workspace or Microsoft 365, the record is still required—the providers handle the server side, but they won’t issue reports unless the DNS opt‑in is present. Check their documentation for any extra settings.