Java Email Verification SDK — Verify Emails in Java

Add the Java email verification SDK to your project using Maven or Gradle. For Maven, add the org.emailvalidationtool:emailvalidationtool dependency to your pom.xml. For Gradle, add implementation 'org.emailvalidationtool:emailvalidationtool:1.0.0' to your build.gradle. The SDK requires Java 11 or higher and uses the built-in java.net.http.HttpClient for HTTP communication, keeping external dependencies to zero. It is published on Maven Central, so no additional repository configuration is needed.

Create an EmailValidationTool instance using the builder pattern. The builder accepts your API key, an optional timeout duration, retry configuration, sandbox mode toggle, and a custom base URL. The resulting client is fully thread-safe and uses connection pooling internally, so you should create a single instance and share it across your application. For Spring Boot projects, add the ev-spring-boot-starter dependency and set ev.api-key in your application.yml or application.properties. The starter auto-configures an EmailValidationTool bean that you can inject into any component using @Autowired.

The Java SDK uses checked exceptions within the org.emailvalidationtool.exceptions package. The base exception EvException is extended by AuthenticationException for invalid API keys, RateLimitException for quota overages, ValidationException for malformed input, and NetworkException for connectivity issues. Each exception provides getStatusCode(), getErrorCode(), and getMessage() methods for programmatic error handling in your catch blocks.

The SDK automatically retries transient failures with exponential backoff. Configure retry behavior through the builder with maxRetries() and retryDelay(). The RateLimitException includes a getRetryAfter() method returning a Duration indicating the wait time. For batch operations, individual failures are captured in each result's getError() method rather than throwing exceptions. Use verifier.getRateLimitRemaining() to monitor your remaining quota. In Spring Boot applications, you can use @ExceptionHandler to map SDK exceptions to appropriate HTTP responses.

import org.emailvalidationtool.EmailValidator;
import org.emailvalidationtool.exceptions.*;

EmailValidationTool verifier = EmailValidationTool.builder()
    .apiKey("YOUR_API_KEY")
    .maxRetries(3)
    .build();

try {
    var result = verifier.verify("user@example.com");
    System.out.println("Status: " + result.getStatus());
} catch (RateLimitException e) {
    System.out.printf("Rate limited. Retry after %d seconds.%n",
        e.getRetryAfter().getSeconds());
} catch (AuthenticationException e) {
    System.err.println("Invalid API key. Check EV_API_KEY.");
} catch (ValidationException e) {
    System.err.println("Invalid input: " + e.getMessage());
} catch (EvException e) {
    System.err.printf("Error: %s (code: %s)%n",
        e.getMessage(), e.getErrorCode());
}