Taking Corvane Trade Supplies' email authentication from monitoring to enforcement: the forged bank-details email that DMARC at p=none let through to 2,340 inboxes, costing nine customers £388,450; the eight-layer defence stack of SPF, DKIM, DMARC, reporting, senders, domains, enforcement and receiver signals, each with its own record and measured result, from 12 SPF lookups cut to 3 and 2048-bit keys to aligned pass rising from 74.3 to 98.6 per cent; and the staged policy ladder from none through quarantine to reject, after which 4,606 of 4,610 spoofs were refused.

CY-EXPERT-093Expert Level · Email Security

Email Authentication Control Challenge

An expert-level course on testing whether an organisation's SPF, DKIM and DMARC controls actually protect its domains, and driving the programme from monitoring to enforcement without breaking legitimate mail. Work the defence stack - eight layers from the SPF record at the base to receiver signals at the top: what SPF proves and why twelve lookups and forwarding defeat it; DKIM signing in the organisation's own name with keys it can account for; alignment, policy, pct and the subdomain gap; aggregate reports read until every sender is known; third-party senders aligned or moved to subdomains; parked and non-sending domains locked down; staged quarantine and reject with measured impact; and monitoring, lookalikes, inbound enforcement and evidence a risk committee can govern.

18 hours8 chapters32 lessons225 activities8 labs

What you'll learn

Reconstruct a spoofing incident from the organisation's own records, explain what SPF proves, trim an include chain on evidence, and measure SPF's failure on forwarding.
Sign every internally run stream in the organisation's own name, inventory and revoke orphaned DKIM selectors, and rotate keys with a safe overlap.
Measure alignment stream by stream, choose alignment modes on evidence, interpret p and pct precisely, and close the subdomain gap with sp.
Build a complete aggregate-report pipeline, reconcile dashboards with raw reports, attribute every source, and separate forwarding from failure.

Price:৳12,000