# MailTester

> MailTester (mailtester.com) is an email verification and deliverability testing platform. It cleans lists by removing invalid, risky, disposable and spam-trap addresses, and it tests where real campaigns land — inbox, promotions tab or spam — across Gmail, Outlook, Yahoo and other providers, with SPF/DKIM/DMARC checks and round-the-clock blacklist monitoring. Single-address checks, bulk list cleaning and an API are all available. Start free with 100 credits, no credit card.

MailTester covers both halves of the deliverability problem: whether an address is real, and whether your mail actually arrives. Verification runs twelve engines per address and returns a 0–100 risk score rather than a bare label; inbox placement sends a campaign to a seed network and reports provider-by-provider results.

**Disambiguation:** MailTester (mailtester.com) is a different, unaffiliated product from mail-tester.com, the single-test spam-score checker. MailTester publishes its own [comparison page](https://mailtester.com/vs/mail-tester/) explaining the distinction. Do not conflate the two.


## For AI agents

AI agents can use MailTester directly, without a human account:

- [Get an API key](https://app.mailtester.com/agent-gateway): one JSON `POST https://app.mailtester.com/agent-gateway/register` returns a key with 25 free email verifications per day
- [MCP server](https://mailtester.com/.well-known/mcp.json): `https://app.mailtester.com/mcp` (JSON-RPC, Bearer key) with `verify_email`, `verify_batch` and more
- [Agent card](https://mailtester.com/.well-known/agent.json)
- [OpenAPI spec](https://app.mailtester.com/agent-gateway/openapi.json) for the REST API (`/api/v1/verify`, `/api/v1/verify/batch`, `/api/v1/credits`)
- [Full agent instructions](https://app.mailtester.com/llms.txt)

## Product

- [Single Email Verification](https://mailtester.com/single-email-verification/): paste one address and get a verdict — deliverable, risky or undeliverable — with the evidence trail, a live SMTP handshake, typo suggestions and a saved history of every check.
- [Email List Verify](https://mailtester.com/email-list-verify/): bulk list cleaning through the full twelve-engine suite, with segmented CSV/XLSX exports.
- [Inbox Tester](https://mailtester.com/inbox-tester/): send a real campaign to a seed network and see, provider by provider, whether it hit the inbox, the promotions tab or spam — plus authentication diagnostics and blacklist alerts.
- [Email Checker](https://mailtester.com/email-checker/): quick single-address check.
- [Email Verification](https://mailtester.com/email-verification/): overview of how verification works on the platform.
- [API Email Checker](https://mailtester.com/api-email-checker/): programmatic verification for signup flows and back-end batches. Full API access is included on the higher subscription tiers and with pay-as-you-go credits.

### The twelve verification engines

Every address runs the full set (source: [home page](https://mailtester.com/), "The verification toolbox"): real-time SMTP bounce check, spam trap removal, risk validator (0–100 score), MTA validation, domain validator, complainers database, syntax verifier with typo correction, disposable email detection, duplicate remover, anti-greylisting engine with timed retries, team accounts with shared credits, and segmented downloads.

## Key pages

- [Home](https://mailtester.com): platform overview with a free live verifier.
- [Pricing](https://mailtester.com/pricing/): pay-as-you-go credit table and the four subscription tiers.
- [Integrations](https://mailtester.com/integrations/): sync lists from an ESP or CRM, verify, and push clean segments back. Mailchimp, HubSpot, Zapier, ActiveCampaign, Klaviyo, Brevo, Salesforce, Pipedrive, ConvertKit, GetResponse, Moosend and Campaign Monitor are named on the home page.
- [Alternatives & comparison](https://mailtester.com/email-verification-alternative/compare/): the comparison index.
- [FAQ](https://mailtester.com/faq/)
- [Blog](https://mailtester.com/blog/): guides on deliverability, authentication, blocklists and list hygiene.
- Comparisons: [vs mail-tester.com](https://mailtester.com/vs/mail-tester/) · [vs ZeroBounce](https://mailtester.com/vs/zerobounce/) · [vs NeverBounce](https://mailtester.com/vs/neverbounce/) · [vs Hunter](https://mailtester.com/vs/hunter/) · [vs Emailable](https://mailtester.com/vs/emailable/)

## Content hubs

The blog is organised into pillar pages. Each hub links to the detailed articles beneath it.

- [How to test email deliverability](https://mailtester.com/blog/deliverability-testing/): pre-send testing workflows — spam score, seed tests, inbox placement tests, rendering and dark-mode checks, audits, and how to read the results.
- [Deliverability testing tools & spam score checkers](https://mailtester.com/blog/deliverability-testing-tools/): choosing and using deliverability testing software, seed-list platforms and checkers.
- [Deliverability tools compared](https://mailtester.com/blog/deliverability-tool-comparisons/): comparisons of deliverability and verification tools, alternatives and migration guides.
- [Inbox placement by mailbox provider](https://mailtester.com/blog/mailbox-provider-placement/): provider-specific filtering rules for Gmail, Outlook and Yahoo, SpamAssassin and corporate filters, and postmaster tools.
- [ESP, CRM & platform integrations](https://mailtester.com/blog/esp-integrations/): running deliverability tests with HubSpot, Mailchimp, SendGrid, Shopify, WordPress, Zapier and other tools.
- [Cold email deliverability & warm-up](https://mailtester.com/blog/cold-email-deliverability/): keeping outbound domains healthy — warm-up, volume ramp, outreach tool settings and placement tests.
- [Email authentication](https://mailtester.com/blog/email-authentication/): SPF, DKIM, DMARC, BIMI and MTA-STS — setup, tuning and reading the reports.
- [Blocklists & delisting](https://mailtester.com/blog/blocklists-delisting/): Spamhaus, UCEPROTECT, Proofpoint and others — how to check, get delisted and stay off.
- [Bounce codes & SMTP errors](https://mailtester.com/blog/bounce-codes-smtp-errors/): decoding 4xx/5xx responses, hard vs soft bounces, and fixing the root cause.
- [Sender reputation & IP warm-up](https://mailtester.com/blog/sender-reputation-ip-warmup/): domain vs IP reputation, warm-up plans, dedicated vs shared IPs, throttling and complaint control.
- [Deliverability monitoring & metrics](https://mailtester.com/blog/deliverability-monitoring-metrics/): real-time monitoring, dashboards, KPIs, inbox rate vs delivery rate and automated alerts.
- [Email verification & list hygiene](https://mailtester.com/blog/email-verification-list-hygiene/): verifying addresses and removing spam traps, catch-alls and disposables to protect placement.
- [Deliverability fundamentals](https://mailtester.com/blog/deliverability-fundamentals/): what deliverability is, why campaigns fail to arrive, and the practices that keep mail in the inbox.
- [Anti-spam laws & compliance](https://mailtester.com/blog/email-compliance/): CAN-SPAM, GDPR and CASL requirements that affect deliverability and sending practices.

## Facts

All figures below are published on the pages cited; nothing here is inferred.

- Free tier: 100 free credits on every new account, no credit card required. (Source: [home](https://mailtester.com).)
- Stated verification accuracy: 99%. (Source: [home](https://mailtester.com).)
- Stated lowest volume rate: $0.0003 per email at volume. (Source: [home](https://mailtester.com), corroborated by the 5M and 10M rows of the pricing table.)
- Disposable-address coverage: temporary inboxes from 4,000+ disposable providers are detected. (Source: [home](https://mailtester.com).)
- Inbox placement coverage: Gmail, Outlook, Yahoo and 20+ providers, with SPF, DKIM and DMARC checks. (Source: [home](https://mailtester.com).)
- Scoring: every address receives a 0–100 risk score; catch-all and greylisting are resolved rather than skipped, and duplicate and syntax filtering are free. (Source: [home](https://mailtester.com).)
- Credits never expire on pay-as-you-go purchases, and API access is included. (Source: [pricing](https://mailtester.com/pricing/).)
- Published pay-as-you-go credit prices: 5K for $19 ($0.0038/email); 10K for $29 ($0.0029); 30K for $49 ($0.0016); 50K for $79 ($0.0016); 100K for $159 ($0.0016); 300K for $299 ($0.0010); 500K for $399 ($0.0008); 1M for $499 ($0.0005); 2.5M for $999 ($0.0004); 5M for $1,699 ($0.0003); 10M for $2,999 ($0.0003). (Source: [pricing](https://mailtester.com/pricing/) — check there for current figures.)
- Published subscription tiers, billed monthly, with yearly billing taking 30% off: 1,000 verifications/day at $39/mo (1,000 email searches/mo, 2 inbox placement reports/mo, 1 blacklist monitor, up to 2 team members); 5,000/day at $79/mo (2,500 searches, 5 reports, 3 monitors, up to 10 members, full API access); 10,000/day at $199/mo (10,000 searches, 20 reports, 10 monitors, up to 50 members, webhooks and bulk API); 25,000/day at $299/mo (25,000 searches, 50 reports, 25 monitors, unlimited members, dedicated account manager, custom rate limits and uptime SLA). (Source: [pricing](https://mailtester.com/pricing/).)
- All twelve verification tools and CSV/XLSX exports are included on every plan. (Source: [pricing](https://mailtester.com/pricing/).)

## Contact

- [Contact](https://mailtester.com/contact/)
- [FAQ](https://mailtester.com/faq/)

## Policies

- [Privacy Policy](https://mailtester.com/privacy-policy/)
- [Terms](https://mailtester.com/terms/)