Domain Search API (V2)

Domain search is functionally similar to email address inquiry but instead attempts to detect possible patterns a specific company uses. You can use detected patterns to help you approximate the correct email for a specific person you’re attempting to contact at a business.

Privacy and security note – Domain Search API searches are performed in real time and do not use stored or processed customer data. Customer privacy and security are and will always remain our top priority.

How to use the Domain Search API

Domain search only requires the domain or company name – no first or last name is necessary.

Before you begin, ensure that your account has enough credits or subscription queries. A successful domain search will consume one (1) subscription query or 20 credits.

If the response is undetermined, no credits or queries will be deducted.

To use the Email Finder API, use the following URL, method, and parameters. Be sure to review the successful response example below and response details to ensure your API configuration works correctly.

API DEFAULT URL: https://api.zerobounce.net/v2/guessformat
API U.S.A. URL*: https://api-us.zerobounce.net/v2/guessformat

Method: GET

*This endpoint uses servers located within the United States. By using this endpoint, you acknowledge and consent to your data being processed on servers in the United States.

  • Parameter
    Required
    Description
  • api_key
    Yes
    Your API Key, found in your account.
  • domain
    Yes
    The email domain for which to find the email format.
  • company_name
    Yes
    The company name for which to find the email format.

Note: Either the “domain” or the “company_name” must be entered

Successful Response


      {
        "domain": "example.com",
        "company_name": "Example Company LLC",
        "format":"first.last",
        "confidence": "high",
        "did_you_mean": "",
        "did_you_mean": "",
        "failure_reason": "",
        "other_domain_formats": [
            {
                "format": "first",
                "confidence": "high"
            },
            {
                "format": "last.first",
                "confidence": "high"
            },
            {
                "format": "lastfirst",
                "confidence": "high"
            }
        ]
      }

Response Details

  • Properties
    Description
  • domain
    The provided domain name.
  • company_name
    The company associated with the domain.
  • format
    The Format of the resulting email addresses.
  • confidence
    The level of confidence we have in the provided format based on our engine and database. Possible values: LOW, MEDIUM, HIGH, UNKNOWN.
  • did_you_mean
    e.g. a suggestion in case case a firstname is used in the lastname field.
  • failure_reason
    useEmailFinderAPIresponse_Description_Failure_Reason
  • other_domain_formats
    A list of domain formats we have for the specified domain. This list contains other formats(e.g. first_name, first, first.last etc.) and the level of confidence we have in the respective format.

Code Samples

Possible failure reasons for unknown status

  • Reason
    Description
  • FREE_DOMAIN_ERROR
    Cannot find pattern for free domains
  • DOMAIN_SYNTAX_ERROR
    Domain syntax error
  • COMPANY_DOMAIN_ERROR
    Either the domain or the company name must be entered
  • COMPANY_DOMAIN_NOT_FOUND
    There is no domain assigned for this company name
  • UNEXPECTED_ERROR_OCCURRED_DURING_VALIDATION
    Unexpected error occurred during validation
  • DOMAIN_DOES_NOT_ACCEPT_MAIL
    Domain does not accept mail
  • NO_DATA_FOR_THIS_DOMAIN
    No data for this domain
  • NO_DATA_FOR_THIS_COMPANY
    No data for this company

Other potential error messages


      {
        "Message": "Invalid API key or your account ran out of credits"
      }

You can resolve this error by ensuring that there is at least one (1) subscription query or 20 ZeroBounce credits in your account balance before making your next API call. Additionally, ensure that the API key is valid.

Domain Search API confidence levels

For each format, the Domain Search API identifies, we assign a corresponding confidence level to indicate the probability that the address is actively used in the respective email domain.

The confidence levels are listed below:

  • LOW - unlikely to be in use; high-risk
  • MEDIUM - medium level of confidence; the format may be in use
  • HIGH - highest level of confidence, format likely in use based on validation results
  • UNKNOWN - see above section for possible unknown errors
  • UNDETERMINED - cannot determine email, so format is unknown. Confidence for an empty email cannot be determined.

If you need further assistance configuring the Domain Search API or need help to understand your results, the ZeroBounce customer support team is available 24/7.