API use case: prevent fraudulent account registrations

You can use our service to help you minimize / prevent fraudulent account registrations where one user can register multiple accounts with disposable email addresses. Such users can consume a lot of your resources (CPU, bandwidth, support, etc.) and cost you a lot of money. This is especially problematic for new & small companies with very limited budgets. Our service can help you detect such fraud.

Flow example:

  1. Your user tries to register account and provides you with email address (usually you would automatically send email verification link to this address, but now you delay this step until you receive feedback from our API).
  2. Your backend calls our REST API method domain/is-temporary with email address or email domain without username
  3. Your backend receives real time JSON response:
    • If result property equals to Yes then this email domain was explicitly marked as disposable / temporary by our moderator. You can safely reject such account registration.
    • If result property equals to No or AutoGeneratedScore you can additionally look into trustLevel score (decimal value between 0 - lowest trust and 1 - highest trust). Based on this value you can decide if account registration should be rejected or accepted.

Our algorithm can automatically classify unknown / new email domains and assign them trustLevel score. Such domains will have "result": "AutoGeneratedScore" until moderator manually classifies them. In this case your decision should be based on trustLevel score.

trustLevel score for confirmed disposable emails have always value of 0.0. To include new / unconfirmed disposable domains and domains with bad reputation, you could decide to reject all requests with trustLevel score lower than 0.2 (or some other threshold value you select). To prevent false positives you could manually review requests with AutoGeneratedScore and low trustLevel score before rejection.

Available REST methods

Method Free Description
domain/is-temporary Check if email address or domain is known temporary / disposable / throwaway email provider.
domain/is-free Check if email address or domain is known free email provider.
verify coming soon Verify mailbox availability.


Free Tier

0 EUR / mo

  • 100 free monthly requests


50 EUR / 25,000 50,000 requests

  • You only pay for what you use, request by request. 1 credit = 1 request
  • Receive additional 25,000 free requests during promotional period, 50,000 requests in total
  • Credits are valid for max one year
  • Volume discount is available


Customizable platform with the highest level of service, priority support available

No credit card needed for free tier

How does it work?

Our email categorization API backend uses following techniques:

  • algorithm first checks if email domain was previously manually classified by our moderator
  • our machine learning algorithm can automatically classify unknown / new email domain and assign trustLevel score in real time, based on multiple data signals