MailboxValidator Free Email Checker

Name: MailboxValidator Free Email Checker API
Brand: MailboxValidator Free Email Checker
Availability: InStock

★ Only Publicly Available OpenAPI DocumentData EnrichmentContact EnrichmentapiKey1 EndpointsREST

For Agents

Connect the MailboxValidator Free Email Checker to your agent

Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the MailboxValidator Free Email Checker, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.

Install Jentic One Beta (Self-Hosted)

Jentic One Host machine

# On the machine that will host your Jentic One instance:
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh

Agent machine

# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL https://raw.githubusercontent.com/jentic/jentic-one/main/tools/install.sh | sh
jentic register       # connects your agent to your Jentic One instance

Jentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.

Capabilities

What an agent can do with MailboxValidator Free Email Checker API.

Classify an email address as free-provider or business via a single GET

Return JSON or XML output controlled by a format query parameter

Distinguish gmail, yahoo, hotmail, outlook and similar consumer domains

Support a credit-based usage model with a per-key API key parameter

GET STARTED

Start building with MailboxValidator Free Email Checker API

Explore with Jentic

View OpenAPI Document

Jentic publishes the only available OpenAPI document for MailboxValidator Free Email Checker, keeping it validated and agent-ready.

MailboxValidator Free Email Checker is a single-purpose endpoint that determines whether an email address comes from a free email provider (gmail.com, yahoo.com, outlook.com and similar). The API returns a JSON or XML response indicating the free-provider verdict for one email at a time and is typically used as a lead-quality signal in CRM pipelines. The OpenAPI spec exposes one operation: GET /v1/email/free.

Use Cases

Patterns agents use MailboxValidator Free Email Checker API for, with concrete tasks.

★ B2B Lead Quality Filter

Filter out free webmail addresses from inbound lead forms so sales reps focus on prospects with corporate domains. The Free Email Checker returns a simple boolean-style verdict per address, which can be wired into a Marketo or HubSpot workflow as a routing condition. A typical setup adds the free-provider flag to the lead record at create time.

For each new HubSpot contact, call GET /v1/email/free?email={email}&key={key} and write the is_free boolean to a custom property.

Trial Abuse Reduction

Reduce trial abuse by flagging or limiting accounts created with free webmail providers. Combined with a disposable-email check, the free-provider flag is a strong signal that a signup will not convert to a paid customer. This is a single GET per signup and adds negligible latency.

Call /v1/email/free for trial@gmail.com and if is_free is true, gate the trial behind manual review.

Agent-Driven Lead Scoring

An AI agent that scores incoming leads can call the Free Email Checker through Jentic to add an is_free signal to its scoring vector. Combined with company enrichment, the agent can autonomously route corporate leads to AEs and free-mail leads to a self-serve nurture track without human intervention.

Run /v1/email/free on a batch of 200 lead emails and tag each lead in Salesforce with a free_email custom field for routing rules.

Key Endpoints

1 endpoints — mailboxvalidator free email checker is a single-purpose endpoint that determines whether an email address comes from a free email provider (gmail.

METHOD

PATH

DESCRIPTION

GET

/v1/email/free

Check whether an email address is from a free email provider

GET

/v1/email/free

Check whether an email address is from a free email provider

Why though Jentic?

Three things that make agents converge on Jentic-routed access.

Credential isolation

The MailboxValidator API key is stored encrypted in the Jentic vault and appended to the key query parameter at execution time. The raw key never enters agent context or logs.

Intent-based discovery

Agents search Jentic by intent (e.g., "detect free email provider") and Jentic returns the GET /v1/email/free operation with its parameter schema for direct execution.

Time to first call

Direct integration: an hour or two to wire up the key, query string, and JSON parsing. Through Jentic: under 15 minutes — search, load, execute.

Related APIs

Alternatives and complements available in the Jentic catalogue.

Complementary

MailboxValidator Disposable Email Checker

Companion endpoint that detects disposable email providers from the same vendor.

Pair with the Free Email Checker when you also need to filter throwaway addresses (10minutemail, mailinator) at signup.

Complementary

MailboxValidator Email Validation

Full single-email validation with MX, SMTP, syntax, and deliverability scoring.

Use the full validation endpoint when a single boolean free-provider verdict is not enough and you need MX or SMTP confirmation.

Alternative

mailboxlayer

Real-time email validation with a free_provider flag plus deliverability score.

Choose mailboxlayer when you want a single API call that returns free-provider, disposable, MX, and score together.

FAQs

Specific to using MailboxValidator Free Email Checker API through Jentic.

What authentication does the Free Email Checker use?

The endpoint takes an API key passed as the key query parameter alongside the email being checked. The OpenAPI spec does not declare a securityScheme component; the key is documented at https://www.mailboxvalidator.com/api-email-freem. Through Jentic the key is stored encrypted and injected at execution time.

Can I get JSON or XML back from this endpoint?

Yes. GET /v1/email/free accepts a format query parameter that selects either JSON or XML output. JSON is the default and the recommended choice for agent and SDK consumers.

What are the rate limits for the Free Email Checker?

MailboxValidator uses a credit model rather than a fixed per-second rate limit. Each call against /v1/email/free consumes credits from your subscription, and the free tier provides a fixed monthly allowance. The OpenAPI spec does not encode a per-second throttle.

How do I check whether an email is free through Jentic?

Search Jentic for "check free email provider" to load the GET /v1/email/free operation, then execute with email and key parameters. The response is a JSON object whose is_free field is the verdict you want.

Is the Free Email Checker available on a free plan?

Yes. MailboxValidator publishes a free tier with a monthly credit allowance for the Free Email Checker. Paid tiers raise the credit cap and unlock other MailboxValidator products such as the disposable checker and full single-validation API.