EML viewer
Drop in an EML or HTML file to inspect its headers, rendered email, source code, and available attachments directly in your browser.
Use free tool Free email tool
Find the tools hiding behind a received email.
Upload an EML file to scan its headers, links, and HTML for signals from popular email platforms, delivery providers, analytics tools, and authentication systems.
- No signup
- Free to use
- Detected email technologies and matched signals
Free browser tool
Email technology checker
The EML file is analyzed locally and is not uploaded to Hypermatic.
Choose an EML file to begin.
How it works
From input to useful result in three steps.
- 1
Save the email you want to inspect as an EML file.
- 2
Drop it into the checker to scan headers, links, domains, and markup.
- 3
Review each detected technology and the exact signals behind the match.
Need the whole email?
Design it in Figma. Export production-ready HTML with Emailify.
This free tool handles one small job. Emailify handles the complete workflow: responsive design, reusable components, breakpoint previews, and HTML export for Gmail, Outlook, Apple Mail, and 40+ email platforms.
Questions
Email technology checker FAQ
How does the email technology checker work?
It looks for known platform-specific headers, sending and tracking domains, link patterns, and HTML fingerprints inside the EML source. Every result includes the signal that triggered it.
Can it identify every email platform?
No. Providers change their headers and domains, white-label infrastructure, and sometimes deliberately remove identifying signals. A no-match result only means no known fingerprint was found.
Is the EML file uploaded for analysis?
No. Detection runs locally in your browser. External assets inside the email are not loaded by this checker.
Free practical guide
How to identify the sending platform and technology behind an email
Received emails often retain clues about the software and infrastructure used to create, send, track, and authenticate them. An email technology checker searches those clues, but its output should be treated as evidence rather than a guaranteed identification of the sender’s complete technology stack.
Quick answer
Save the received message as an EML file and scan it with the free checker above. It looks for recognizable headers, tracking domains, link patterns, HTML fingerprints, and SPF, DKIM, or DMARC results. Each match includes the signal that produced it so you can judge the evidence yourself.
Which parts of an email reveal its technology?
The strongest clues often live in transport headers that normal inbox interfaces hide. Providers may add identifiers, campaign IDs, bounce domains, return paths, or routing headers. Rewritten links and image URLs can also expose tracking or delivery domains associated with a particular platform.
HTML fingerprints are usually weaker evidence because templates, editors, and sending providers can be combined. A campaign might be designed in one product, exported through another, sent through a delivery API, and measured with a separate analytics service. A useful checker therefore reports categories and matched signals rather than forcing one simplistic answer.
| Signal | What it may reveal |
|---|---|
| Provider headers | A campaign platform, delivery service, or internal message identifier. |
| Tracking domains | Click measurement, open tracking, or redirect infrastructure. |
| Return-Path and Received headers | Bounce handling and parts of the delivery route. |
| HTML comments and markup | An editor, template system, or testing platform. |
What do SPF, DKIM, and DMARC results tell you?
SPF checks whether the sending server was authorized for an envelope domain. DKIM verifies a cryptographic signature added by a signing domain. DMARC evaluates alignment between authenticated domains and the visible From domain, then applies the domain owner’s policy.
A pass or failure helps assess authentication, but it does not identify the entire marketing stack. A company can authenticate a branded domain while using shared delivery infrastructure, and several products may use the same underlying email service. Authentication results are one evidence layer, not a vendor invoice.
Why can email-platform detection be uncertain?
Platforms change headers and domains, enterprise accounts use custom tracking domains, and white-label systems intentionally hide vendor branding. Forwarding, security gateways, mailing lists, and inbox providers can add or rewrite evidence after the original send. Some EML exports also omit headers available in the raw source.
For a more reliable conclusion, compare several recent emails from the same sender and prioritize repeated, provider-specific signals. A single generic domain or familiar HTML pattern should not outweigh conflicting transport evidence.
- Prefer exact provider-specific headers over generic HTML structure.
- Distinguish the campaign platform from the underlying delivery provider.
- Treat custom domains as possible branded aliases, not immediate no-match evidence.
- Record the matched signal so another person can reproduce the conclusion.
When is an email technology checker useful?
Technology detection is useful for competitive research, migration discovery, deliverability troubleshooting, agency handovers, and understanding an inherited campaign workflow. It can quickly narrow the list of platforms worth investigating without requiring access to the sender’s account.
Use the free local checker when you need a fast, explainable scan of one EML file. Do not use a fingerprint result as proof of ownership, security posture, legal compliance, or current subscription status; those questions require direct confirmation from the organization involved.
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