100 credits on us · no card required

Know which emails deserve to be sent.

Verify one address in real time or clean an entire list. Get the evidence your team needs—from basic domain checks to SMTP mailbox confirmation—without paying for inconclusive API results.

Start free Explore the API

No credit card
100 free credits
Credits never expire

Deepcheck · 2 credits

Verification resultLive

alex@northstar.io92

Address status

Ready to send

Low-risk address with mailbox evidence

Syntax + domainPass

DisposableNot detected

MailboxDeliverable

Catch-allNo

Unknown results refunded

Built for the way teams verify

Real-time API

Bulk CSV + TXT

MCP for AI tools

Three verification depths

Protect more than one send

A wrong address can cost domain trust—not just delivery.

Repeated hard bounces can signal poor list hygiene and put sender reputation at risk. Verify before sending so avoidable bad addresses never reach the send queue.

VerifyRemove bad addressesProtect reputation

A verification system, not a black box

Every result comes with a reason.

Choose the right amount of evidence for each decision, then carry the result into your product, list workflow, or AI tool.

Single API + bulk jobs

Verify one email—or an entire list

Use the real-time API inside your product or upload CSV and TXT files from the dashboard. Choose the depth that fits each workflow.

Explainable risk signals

See why an address is risky

Go beyond a pass/fail label with syntax, MX, disposable, role-based, TLD, provider, authentication, blocklist, WHOIS, and parked-domain signals.

Mailbox-level evidence

Confirm the mailbox when it matters

Deepcheck adds SMTP mailbox and catch-all verification for high-value sends—without sending an email to the recipient.

MCP-ready

Put verification inside AI workflows

Connect the MailTooth MCP server and let supported AI tools verify an address before outreach, CRM entry, or messaging.

Teams + API analytics

Operate as a team

Invite teammates, manage workspace permissions, create scoped API keys, and inspect usage and verification activity in one place.

Automatic refunds

Spend credits on conclusive results

Unknown API outcomes and failed executions are automatically refunded. Purchased credits never expire, so unused budget stays yours.

Progressive verification

Use deeper checks only when the decision needs them.

A form validation and a high-value outbound email should not cost—or wait—the same.

Quick

Form checks and large first-pass lists

Fast address and domain screening before data enters your system.

Syntax and domain
MX records
Disposable and role-based
Personal vs professional
TLD risk and name signals

Standard

CRM hygiene and campaign preparation

A richer domain-trust profile without an SMTP mailbox check.

Everything in Quick
Email provider detection
SPF, DKIM, and DMARC
Blocklist and parked-domain risk
WHOIS domain context

Deepcheck

High-value outreach and critical sends

The complete check, including mailbox-level deliverability evidence.

Everything in Standard
SMTP mailbox verification
Catch-all detection
Deliverability score
Evidence from attempted MX hosts

Unknown should not cost the same as known.

Unknown API outcomes and failed executions are automatically refunded.

From raw address to clear next step

One contract. Multiple ways to work.

Start in the dashboard, integrate the endpoint, or place verification inside an AI workflow. The same tiered model keeps decisions consistent.

Read the product docs

Choose the input

One address via API or MCP, or a CSV/TXT file in the dashboard.

Set the evidence level

Quick, Standard, or Deepcheck—based on the decision you need to make.

Act on explicit signals

Keep, reject, retry, or review using address, mailbox, and risk evidence.

MCP for agentic workflows

Give every agent a deliverability checkpoint.

Connect the MailTooth Streamable HTTP MCP server and verification becomes a native tool call. Your agent can check an address, receive structured evidence, and choose the next action before it writes to a CRM, starts outreach, or triggers a message.

Connect the MCP server Read the agent workflow guide

AGENT

Before creating this CRM contact, I need to confirm the address.

TOOL CALLverify_email

{ email: "alex@northstar.io", type: "deepcheck" }

addressStatusvalid

mailbox.statusdeliverable

risk.levellow

NEXT ACTION

Create contact and continue the approved workflow.

One tool, explicit evidence.

The agent receives address status, mailbox status, risk, disposable and role-based flags, credit usage, and the complete structured result.

Policy stays in your control.

Tell the agent when to use Quick, Standard, or Deepcheck and which outcomes require review.

No guesswork in the prompt.

The agent calls the same verification engine used by the API and bulk workflows.

Before CRM write

Lead-intake agents

Verify a discovered address before the agent creates a CRM contact, assigns an owner, or starts an outreach sequence.

Before message send

Outbound agents

Run Deepcheck for high-value recipients and let mailbox, catch-all, and risk signals decide whether to send, review, or stop.

Before workflow trigger

Signup and onboarding agents

Use a fast address check before an automated workflow accepts a user, sends an invitation, or starts onboarding.

Before data activation

Data-hygiene agents

Recheck stale records and route explicit invalid, unknown, disposable, role-based, and risky outcomes to different actions.

Works with compatible Streamable HTTP MCP clients and agent frameworks—including Claude Code, Cursor, VS Code, Windsurf, OpenAI Agents, and custom clients.

Built around real workflows

A better answer for every team that depends on email.

Explore focused playbooks for preventing bad data, reducing avoidable bounces, and choosing the right verification depth.

Cleaner product data

SaaS & product teams

Stop bad addresses at the edge of your productExplore workflow

More confident outreach

Sales & lead generation

Qualify the address before your rep presses sendExplore workflow

Repeatable client hygiene

Marketing agencies

Clean every client list with one accountable workflowExplore workflow

Reach the right candidates

Recruiting & staffing

Keep candidate outreach from ending at a dead addressExplore workflow

Fewer unreachable customers

Ecommerce & marketplaces

Catch invalid customer emails before they break the journeyExplore workflow

Evidence-rich data products

B2B data platforms

Add verification depth without building SMTP infrastructureExplore workflow

Pay once. Verify when needed.

Credits that wait for you.

No monthly plan to babysit. Start with 100 credits, then buy a pack that fits your workload. Purchased credits never expire.

from$11for 3,600 credits

See all pricing

Starter3,600 credits

$11

GrowthMost popular10,200 credits

$27

Pro32,600 credits

$72

ScaleBest value55,000 credits

$111

Custom packs are available from $111

The verification field guide

Practical answers for cleaner sending.

Product guidance and deliverability fundamentals from the team building the verification engine.

View all articles

Agent workflows

Aug 13, 20268 min read

How to give AI agents an email verification checkpoint with MCP

Connect verification as a native agent tool, then use structured address, mailbox, and risk signals to make safer workflow decisions.

Read article

Product guide

Aug 12, 20266 min read

Quick, Standard, or Deepcheck: choosing the right verification depth

A practical framework for balancing speed, evidence, and credit usage across forms, lists, and high-value sends.

Read article

Deliverability

Aug 8, 20267 min read

How to clean an email list before a campaign

A simple, repeatable process for preparing CSV or TXT contact data without losing the reasoning behind each result.

Read article

Good questions deserve direct answers

Frequently asked questions

Still deciding how verification fits your workflow? Start free and inspect real results before buying credits.

Get 100 free credits

01What does MailTooth verify?+

Depending on the selected depth, checks include syntax, domain and MX records, disposable and role-based addresses, personal or professional classification, TLD risk, provider detection, parked domains, SPF/DKIM/DMARC, blocklists, WHOIS, SMTP mailbox status, and catch-all behavior.

02Do I need a credit card to start?+

No. New accounts receive 100 verification credits and can begin without adding a card.

03Do purchased credits expire?+

No. Credit packs are one-time purchases and purchased credits do not expire.

04What happens when a verification is inconclusive?+

Unknown API outcomes and failed executions are automatically refunded, so those checks do not consume your credit balance.

05Can I verify a file without writing code?+

Yes. Upload a CSV or TXT file in the dashboard, select the email column and verification depth, follow the job progress, and download the completed results.

06Can developers verify emails in real time?+

Yes. Create a scoped API key and call the single-email verification endpoint. The product documentation includes request and response examples for all three depths.

07Does MailTooth work with AI tools?+

Yes. The Streamable HTTP MCP endpoint exposes a verify_email tool for compatible AI clients and agent frameworks, using the same tiered verification model, structured results, and API-key authentication.

08Can invalid email addresses hurt sender reputation?+

Repeated hard bounces can signal poor list hygiene and put domain and sender reputation at risk. Verifying before a send reduces avoidable bad-address attempts, but it should complement—not replace—consent, authentication, and responsible sending practices.

09Does verification send an email to the recipient?+

No. Deepcheck uses SMTP-level signals without sending a message to the address being checked.

Your first 100 credits are free

Clean data in. Better sends out.

Start without a card. Add credits only when the product has proved its value to your workflow.

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