Reconnect with lost customers by locating up to 5 new email addresses using an old, non-responsive or undeliverable email address.

Making a Request

The AppendEmail method leverages the same low level search functions and data sources used in our Batch Email Append service. Pass your existing contact information such as first name, last name, city, state, and physical address to look-up the email address(es) associated with your customer.

Output Email Address Verification

Output email addresses can be verified in real-time by pinging the ISP to determine deliverability status with 90% accuracy. Output email addresses are also scanned by a real-time SPAM detection algorithm that protects sender reputation by performing over 240 independent, real-time scans analyzing your data for all known problematic or non-deliverable email addresses. Set input parameter verifyDeliverableEmail=true to verify output email addresses.


HTTP Headers

The "content-type" in the HTTP header must be set to "application/json", otherwise an HTTP 400 Bad Request response will be returned.

Response Definitions

A single response may include multiple Email addresses. A match level is returned for each email address to indicate the context in which the match was made.

Field nameTypeDescription
EmailstringFully verified email address
FirstNamestringListing identity's first name
LastNamestringListing identity's last name
MatchLevelstringIndicates the MatchLevel under which the match was found.


The MatchLevel response field indicates how well the request fields sent to the API match the response fields. For example, a MatchLevel returned of E1 might be considered an exact match whereas a return of E2 reveals that the first name of the individual does not necessarily match the request fields. Click to see the MatchLevel codes and descriptions.

HTTP Error Messages

Click to see a complete listing of error messages and codes.

Click Try It! to start a request and see the response here!