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Glossary

The email & data verification glossary

Plain-English definitions for everything in email verification, phone validation, deliverability and contact data. Pick a term to learn what it means and what to do about it.

Email verification→

The process of checking whether an email address is real and able to receive mail, without sending one.

Catch-all email→

A domain configured to accept mail for every address, so a verifier can't confirm a specific mailbox exists.

Disposable email→

A temporary, throwaway address from a service designed to self-destruct after short-term use.

Hard bounce vs soft bounce→

A hard bounce is a permanent delivery failure; a soft bounce is a temporary one.

Sender reputation→

A trust score mailbox providers assign to your sending domain and IP that decides inbox vs spam.

Spam trap→

An email address used by providers and blocklists to catch senders with poor list hygiene.

Role-based email→

An address tied to a function rather than a person, like info@ or sales@.

MX record→

A DNS record that tells other servers where to deliver email for a domain.

SPF→

Sender Policy Framework — a DNS record listing which servers may send email for your domain.

DKIM→

DomainKeys Identified Mail — a cryptographic signature that proves an email wasn't altered in transit.

DMARC→

A policy that tells receivers what to do with mail failing SPF and DKIM, plus where to send reports.

Email deliverability→

Whether your email actually reaches the inbox rather than the spam folder or a bounce.

Phone number validation→

Checking whether a phone number is correctly formatted, active and what line type it is.

HLR lookup→

A query against the carrier's Home Location Register to check a mobile number's live status.

Line type (mobile/landline/VoIP)→

Whether a phone number is a mobile, a landline or a VoIP number — which changes how you should reach it.

Data enrichment→

Adding missing context — like company, industry or location — to a contact record.

Firmographics→

Company-level attributes — industry, size, revenue, location — used to segment and score B2B leads.

Company name-to-domain matching→

Resolving a company's name to its primary web domain, a building block of B2B enrichment.

Bounce rate→

The share of sent emails that couldn't be delivered — a key deliverability signal.

List hygiene→

The ongoing practice of keeping a contact list clean, current and deliverable.

Email verification API→

A programmatic endpoint that verifies an address in real time, usually at the point of capture.

Form guard→

Real-time verification on a signup or lead form that blocks fake, invalid or risky submissions.

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