canonical: https://jentic.com/apis/mailboxvalidator.com/mailboxvalidator-validation

# MailboxValidator Email Validation

MailboxValidator Email Validation is the full single-email validation product from MailboxValidator. The `/v1/validation/single` endpoint returns syntax checks, free-provider and disposable flags, MX record presence, SMTP existence, role-account detection, and a numeric MailboxValidator score that summarises overall deliverability. Output is available as JSON or XML and one call covers all the validation signals the vendor exposes.

## For AI agents

Validate one email address and return the full MailboxValidator signal set - syntax, MX, SMTP, free, disposable, role, and score - in a single GET.

## Scope

Does not send email, manage suppression lists, or run bulk validation - use for single-address full validation only.

## Capabilities

- Validate the syntax of an email address against RFC rules
- Confirm MX record presence and run an SMTP existence check
- Flag free-provider, disposable, and role-based addresses in one response
- Return a numeric MailboxValidator score for downstream send/skip logic
- Output JSON or XML controlled by a format query parameter

## Use cases

### Pre-Send Email Verification

Verify each recipient address before queueing a transactional email so bounces never reach the email service provider. The single-validation endpoint returns syntax, MX, SMTP, and a deliverability score in one call, which is everything a sender needs to gate a send. Validation typically runs in under a second and integrates inline with a transactional send pipeline.

Example prompt: Call GET `/v1/validation/single`?email=jane@example.com&key={key} and proceed with the SendGrid send only if score is at least 0.7.

### CRM Import Cleansing

Run every imported CRM contact through MailboxValidator to attach validation metadata to the lead record. Sales reps then see deliverability score, role-based flag, and disposable flag on the contact card before they invest time in outbound outreach. A typical hygiene pass cuts bounce-driven domain reputation damage substantially.

Example prompt: For each new HubSpot contact created today, call `/v1/validation/single` and write score, is_role, and is_disposable to custom contact properties.

### Agent-Driven Lead Qualification

An AI agent that processes inbound demo requests can call MailboxValidator through Jentic to qualify the email before booking a meeting. The score and role flags drive a deterministic accept/route/reject decision, and the agent can chain the call with a calendar API to book reps on the qualified leads only.

Example prompt: Validate every demo-request email through `/v1/validation/single`, then book a Calendly slot only when score is at least 0.7 and is_role is false.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/v1/validation/single` | Run a full single-email validation |

## Key resources

- **Single Validation** — One endpoint returning the full MailboxValidator signal set for an email address

## Why Jentic

- **Setup:** Wiring MailboxValidator Email Validation by hand means attaching your API key to each request, targeting the api.mailboxvalidator.com host, and parsing the full validation result yourself. Through Jentic you install once, import the validation API from the API Directory, store the key once, and your agent calls it.
- **Permission scoping:** This API offers a single-address full validation with the address carried in the request, so limit the agent to the operation it needs, the single validation call, and nothing more. Which operations run is your choice.
- **Credential handling:** Your MailboxValidator API key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
- **Discovery method:** Agents search Jentic by intent such as 'fully validate an email address', and Jentic returns the matching MailboxValidator operation with its input schema so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **MailboxValidator Free Email Checker** — Lighter free-provider-only check against the same MailboxValidator infrastructure.
- **mailboxlayer** — Real-time email validation with MX, SMTP, disposable, and deliverability score.
- **ZeroBounce** — Email validation with AI-scored deliverability and abuse detection.

## FAQ

### What authentication does the Email Validation API use?

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

### Can I get the MailboxValidator score in JSON?

Yes. GET `/v1/validation/single` returns a JSON object that includes the score field plus boolean flags such as is_disposable, is_role, is_free, mx_found, and smtp_check. Set format=xml in the query string to receive XML instead.

### What are the rate limits for the Email Validation API?

MailboxValidator runs on a credit-based usage model rather than per-second throttling. The single-validation endpoint consumes credits from your subscription, and the free tier provides a monthly allowance. The spec does not declare a per-second cap.

### How do I run a single validation through Jentic?

Search Jentic for "validate email mailboxvalidator" to load the GET `/v1/validation/single` operation, then execute with email and key parameters. Inspect score, is_disposable, and smtp_check on the returned JSON object.

### Is the Email Validation API free?

MailboxValidator publishes a free tier with a monthly credit allowance for `/v1/validation/single.` Paid plans raise the credit cap and unlock the bulk validation product offered alongside the single-email endpoint.

### Does the validation endpoint detect role-based addresses?

Yes. The response includes an is_role flag that is true for generic mailbox aliases such as info@, sales@, and support@. Combined with score and is_disposable, the role flag is useful for filtering low-intent leads from B2B campaigns.

### Can I limit what my agent is allowed to do with the MailboxValidator Email Validation API?

Yes. Because you run Jentic One yourself, your own rules decide which operations and credentials the agent may use. This API exposes a single operation, the GET `/v1/validation/single` call, so you can scope the agent to that one validation endpoint and nothing else. Your stored API key is injected only at execution time for the calls you have allowed, keeping the agent limited to full single-address validation.