Understanding Enrichment Data
Fuego returns a rich set of signals for each email address. This guide explains what each field means and how to put it to work.
Category Values
The category field tells you what kind of organization is behind the address:
| Category | Description | Typical Action |
|---|---|---|
| enterprise | A business with roughly 1,000+ employees | Route to sales, high priority |
| smb | A small or medium-sized business | Standard sales/marketing flow |
| education | A school, college, or university | Apply education pricing or messaging |
| government | A government agency or department | Route to your public-sector flow |
| nonprofit | A nonprofit organization | Apply nonprofit pricing or messaging |
| individual | A personal address on a free provider (Gmail, Yahoo, etc.) | Self-serve onboarding |
| disposable | A throwaway/temporary email service | Block or quarantine |
| unknown | The organization could not be determined | Treat as a standard lead |
Risk Levels
The risk field is a simple, opinionated summary you can gate on:
| Risk | Trigger | Recommended Action |
|---|---|---|
| high | Disposable address, invalid syntax, or domain has no MX records | Block the signup or require an extra step (e.g. phone confirmation) |
| medium | Shared role address (info@, admin@, support@, etc.) | Allow, but treat as lower-quality for outreach |
| low | None of the above | Proceed normally |
Flag Fields
| Field | Description |
|---|---|
| syntax_valid | The address passes format checks. Invalid addresses are not charged a credit |
| did_you_mean | Suggested correction for likely typos (gmail.cmo → gmail.com), or null |
| normalized_email | The address with any plus tag stripped (lister+promo@gmail.com → lister@gmail.com). Use it to deduplicate signups |
| disposable | The address uses a throwaway/temporary email service |
| free | The address uses a free consumer provider (Gmail, Yahoo, etc.) |
| role | The address is shared rather than personal (info@, admin@, support@) |
| plus_address | The address uses plus addressing (user+tag@domain) — commonly used to register multiple accounts from one mailbox |
| has_mx | The domain publishes DNS MX records. This is a DNS lookup only — Fuego never connects to mail servers. A missing MX record is a strong signal the address can’t be real |
Organization Intelligence
The organization object describes the organization behind the email domain. Fields are null when unknown:
| Field | Description |
|---|---|
| name | Organization name |
| industry | The organization’s industry, from a fixed list based on the NAICS 2022 subsectors |
| country | 2-letter country code where the organization is based |
| ticker | Stock ticker symbol (if publicly traded) |
| employees | Approximate number of employees |
| employee_range | One of: 1-10, 11-50, 51-200, 201-500, 501-1000, 1001-5000, 5001-10000, 10000+ |
| description | Brief description of the organization |
Usage Recipes
Block disposables at signup
Call the API in your signup handler and reject (or quarantine) any signup with risk: "high". This stops throwaway emails, nonsense addresses, and domains that can’t receive mail before they ever reach your database.
if (lead.risk === "high") {
return res.status(422).json({ error: "Please use a real email address." });
}
Catch duplicate accounts from plus addressing
Plus addressing (lister+trial2@gmail.com) is legitimate email behavior, but it’s also the easiest way to sign up for the same service repeatedly — free-trial abuse, referral fraud, one-vote-per-account schemes. Store normalized_email alongside the raw address and enforce uniqueness on it:
const existing = await User.findBy({ normalizedEmail: lead.normalized_email });
if (lead.plus_address && existing) {
// Same mailbox already has an account — treat as a duplicate
}
Auto-fix typos with did_you_mean
When did_you_mean is set, the user probably mistyped their address. Show a one-click confirmation (“Did you mean lister@gmail.com?”) instead of losing the lead.
Route enterprise leads to sales
When category is enterprise (or government), notify your sales team immediately — these are the signups worth a same-day human follow-up. Everyone else continues through self-serve onboarding.
Segment by employee_range
Use organization.employee_range to drive nurture campaigns and in-product messaging: a 1-10 company gets startup messaging, a 10000+ company gets the security-and-compliance track.
Score your CRM
Run your existing leads through list enrichment and sort by category and employee range. Most teams find high-value accounts that were sitting untouched in their database.
Common Questions
Why might a real business email be categorized as unknown?
Our organization dataset is large but not exhaustive. Newly registered domains, very small companies, and personal domains often have no organization data. The abuse signals (disposable, has_mx, role) still work for these addresses. Unknown results are free — they never count against your quota or trial credits.
Does Fuego check whether a mailbox exists?
No. Fuego never connects to mail servers. We focus on who is behind the address and whether it shows abuse signals, using DNS and our organization datasets. That’s what makes Fuego fast enough to run inside your signup flow.
Should I block all free addresses?
Usually not. Plenty of legitimate users sign up with Gmail or Yahoo. The free flag (and individual category) is best used for segmentation — for example, excluding individuals from account-based marketing — rather than blocking.