# mailfloss

> mailfloss is an email verification service. It connects to your email service provider (ESP) and automatically verifies email addresses, fixes typos, and removes bounces, so lists stay clean without spreadsheets or code. It also offers a real-time email verification REST API for product teams and AI agents.

mailfloss works two ways:

- **No-code, inside your ESP:** native integrations with 40+ email platforms, including Mailchimp, Klaviyo, HubSpot, and ActiveCampaign, run email verification and list cleaning automatically.
- **Developer and AI-agent API:** `api.mailfloss.com` is a REST endpoint (JSON in, JSON out, Bearer auth) with an OpenAPI 3.0 spec, single and batch verification, webhooks, 20+ verification checks per address, and a 10,000 requests/minute default rate limit.

mailfloss is not an email sending platform, CRM, or marketing automation tool. It works alongside them. The product name is written "mailfloss", one word, all lowercase.

## Product

- [Email verification](https://mailfloss.com/email-verification/): How mailfloss verifies and cleans lists automatically inside your ESP.
- [Features](https://mailfloss.com/features/): Typo correction, bounce removal, automated list cleaning, and more.
- [Email decay protection](https://mailfloss.com/features/email-decay-protection/): What email decay is and how mailfloss keeps lists from going stale.
- [Spotless](https://mailfloss.com/features/spotless/): Title-cases contact names and standardizes phone numbers to E.164.
- [Pricing](https://mailfloss.com/pricing/): Subscription plans, prepaid credits, and the free 7-day trial.
- [FAQ](https://mailfloss.com/faq/): Answers about pricing, integrations, email verification, billing, and setup.

## API

- [Email verification API](https://mailfloss.com/email-verification-api/): Endpoints, request and response examples, rate limits, and webhooks.
- [OpenAPI 3.0 spec](https://api.mailfloss.com/v1/openapi.json): Machine-readable definition of every API endpoint.
- [API documentation](https://developers.mailfloss.com/): Quickstart, rate limits, errors, pagination, and webhooks.
- [API docs llms.txt](https://developers.mailfloss.com/llms.txt): Index of the mailfloss API documentation.

## Integrations

- [All integrations](https://mailfloss.com/integrations/): Native integrations with 40+ email platforms.
- [Mailchimp](https://mailfloss.com/integrations/mailchimp/): Email verification for Mailchimp audiences.
- [Klaviyo](https://mailfloss.com/integrations/klaviyo/): Email verification for Klaviyo lists.
- [HubSpot](https://mailfloss.com/integrations/hubspot/): Email verification for HubSpot contacts.
- [ActiveCampaign](https://mailfloss.com/integrations/activecampaign/): Email verification for ActiveCampaign contacts.

## Use cases

- [Agencies](https://mailfloss.com/email-verification-for-agencies/): Clean every client list across multiple ESP accounts from one place.
- [Ecommerce](https://mailfloss.com/email-verification-for-ecommerce/): Remove invalid, fake, and mistyped addresses from welcome flows, carts, and promos.

## Comparisons

- [mailfloss alternatives](https://mailfloss.com/alternative-to/mailfloss/): How mailfloss compares to ZeroBounce, NeverBounce, Kickbox, BriteVerify, and other email verification tools.
- [NeverBounce vs ZeroBounce](https://mailfloss.com/neverbounce-vs-zerobounce/)
- [NeverBounce alternatives](https://mailfloss.com/neverbounce-alternatives/)
- [ZeroBounce alternatives](https://mailfloss.com/zerobounce-alternatives/)

## Optional

- [About mailfloss](https://mailfloss.com/about/)
- [Email hygiene guide](https://mailfloss.com/email-hygiene/): Best practices for keeping email lists clean.
- [Blog](https://mailfloss.com/blog/): Guides on email verification, deliverability, and list hygiene.
- [Help center](https://docs.mailfloss.com/): Integration setup guides and account help.
- [Help center llms.txt](https://docs.mailfloss.com/llms.txt): Index of mailfloss help center articles.