About ESI
Specialist email security education. One subject, taught with depth and rigour.
One subject. Unmatched depth.
The Email Security Institute exists for one reason: to teach email security with unmatched depth and rigour. We do not teach networking, cloud security, or general IT. Email is all we do.
Our content is written, not filmed. Every module is a carefully structured document backed by real verification against live domains and real DNS. We believe practitioners learn by doing, not by watching.
Programmes are maintained by active practitioners who work with email authentication daily. When standards evolve, our content evolves with them, often the same week.
How we teach.
Content-Driven
Written, structured modules designed for deep comprehension. No filler videos or slide decks. Just clear, expert-written technical content.
Verification-Focused
Technical programmes include live verification using the ESI Agent. You work with real domains and real DNS records across production platforms, not simulated environments.
Practically Assessed
Technical certification exams test real skills on real infrastructure. Leadership and awareness programmes use scenario-based assessment.
The ESI Agent.
Our command-line tool connects to your learning environment. Verify DNS records, diagnose authentication issues, get contextual hints, and take exams, all from your terminal.
# Install the CLI Agent
$ npm install -g @emailsec/agent
esi authAuthenticate your CLI sessionesi startStart a module sessionesi verifyVerify your DNS configurationesi hintGet a contextual hintesi statusCheck your progressesi exam startBegin the certification examLightweight Setup
The CLI Agent runs locally and connects to our verification servers. No complex infrastructure setup required.
Real System Verification
Every lab verifies real DNS records on real domains. No sandboxed simulations. Genuine infrastructure.
Self-Updating
The CLI Agent updates itself when new modules or exam versions are released. Always current.
The Email Security
Institute
Authex
Education
ESI trains the practitioners
Tooling
Authex provides the platform
Together
Learn it, then deploy it
Education meets production tooling.
ESI is an Authorised Partner of Authex, the email authentication platform at authex.online. This partnership means our training content is always aligned with production-grade tooling.
Graduates gain hands-on experience with the same tools used by security teams in production. The skills you learn here transfer directly to your day job.
- Free Authex domain scanner for all students
- Graduates receive 3 months of Authex Pro access
- B2B bundles combine training with platform licences
Contact us.
Whether you have a question about a programme, want to discuss corporate training, or just want to say hello, we'd love to hear from you.
hello@emailsecurity.institute
Location
London, United Kingdom
Response time
Within 1 working day
Corporate enquiries
For team licences, private training, and enterprise packages, please use the form or email us directly. We typically respond within a few hours for corporate requests.
Ready to start learning?
Explore our programmes or join a live training session. The next step in your email security career starts here.