Email Hygiene: A Hidden Lever in Reducing Fake Accounts & Improving Business Metrics

Every executive decision relies on trustworthy numbers. Metrics like CAC (Customer Acquisition Cost), CLTV (Customer Lifetime Value), churn, and growth are only as accurate as the data behind them. When fake, synthetic, or compromised email addresses start clogging up your customer account lists, they distort these critical measurements, inflating acquisition costs, diluting lifetime value, and creating churn that doesn’t reflect real customer behavior.

By eliminating fake, compromised, and other high-risk accounts, companies get a clearer picture of their true customer base and a more reliable financial view of their business. This isn’t just a fraud problem, it’s a cross-functional issue that affects how Marketing measures campaign ROI, how Sales forecasts pipeline growth, and how Finance evaluates capital efficiency.

One of the most effective and under-leveraged processes to achieve cleaner data is email account hygiene. This approach evaluates the trustworthiness of an email address at account creation, login, or during ongoing use, helping to detect synthetic identities, compromised accounts, disposable emails, and addresses linked to recent criminal activity. Filtering these out early protects your business and ensures that your growth, retention, and revenue metrics reflect reality rather than noise.

Impact on Business Metrics

Fraud Vector	Signal from Email Reputation	Impact on Business Metrics
Disposable / temporary email addresses	Poor domain reputation, short lifetimes, high churn	Marketing: Campaign performance looks inflated but doesn’t convert. Finance: CAC rises as acquisition spend is wasted
Compromised / breached credentials	Appear in breach dumps or infostealer logs	Fraud: Direct ATO losses. Sales: Inflated LTV that disappears with churn. Finance: Missed revenue forecasts due to account attrition
Synthetic / fake accounts	Detected via email age, domain reputation, behavioral signals	Sales: Inflated pipeline and false “user growth”. Marketing: Campaign ROI reporting skewed. Finance: Overstated revenue potential in models
Observed criminal / fraud activity	Known fraud rings, chargebacks, spam networks	Operations: Reduced manual review and chargeback costs. Customer Experience:  Trust and retention improve. Finance: More predictable fraud loss reserves.

The Bigger Picture Behind the Numbers

The data paints a sobering picture: synthetic and fake accounts aren’t just a nuisance, they are warping the very financial metrics executives rely on to make decisions. TransUnion reports that more than half of financial institutions now see synthetic identities as their top fraud concern. At the same time, the tactics behind these accounts are evolving, with 40% of institutions observing increased fraud attempts tied to generative AI, and nearly a third already facing deepfake-driven synthetic identities. These aren’t fringe issues; they’re mainstream risks undermining the quality of customer data.

It’s not just financial services feeling the impact. Ping Identity highlights a 32% growth in fraudulent new bank accounts in a single year, and a staggering 183% spike in synthetic fraud attempts in retail over a three-year period. These accounts don’t only drain fraud budgets, they inflate Marketing’s lead counts, Sales’ user growth numbers, and Finance’s forecasts. Executives making calls on CAC, LTV, or churn are often doing so with corrupted data sets.

Email Reputation from myNetWatchman Exposes Compromised, Fake Email Accounts

Email Reputation doesn't just reduce fraud losses; it restores trust in the numbers themselves. By filtering out the noise of fake, synthetic and compromised accounts, companies can ensure their financial reporting is grounded in reality. And for business managers, that clarity isn’t a nice-to-have, it’s essential for allocating capital, planning growth, and proving ROI across the organization.

• For Marketing: Better segmentation, cleaner campaign attribution, higher conversion rates

• For Sales: Real pipeline, not padded by synthetic users

• For Finance: Capital efficiency ratios (CAC, payback, LTV/CAC) calculated on real customer, not fake ones

Email Reputation is a simple API that helps companies determine if an email address is trustworthy, fake, synthetic, deliverable, or actively compromised. Businesses use Email Reputation during new account setup, login, and password reset to reduce authentication costs, enhance security, and prevent fraud. The real impact goes beyond fraud to ensure the metrics driving strategy and valuation actually reflect reality.

For more information on Email Reputation by myNetWatchman, click here.