Catch-All Email Verifier - Java Library

Verify emails on catch-all domains with deterministic verification. Most verifiers mark catch-all emails as "risky" or "unknown" -- this one tells you if the specific mailbox actually exists.

Powered by Enrow -- deterministic email verification, not probabilistic.

The catch-all problem

A catch-all (or accept-all) domain is configured to accept mail sent to any address at that domain, whether or not the specific mailbox exists. This means anything@company.com will not bounce at the SMTP level, so traditional email verifiers cannot distinguish real inboxes from non-existent ones. They return "accept-all", "risky", or "unknown" and leave you guessing.

Enrow uses deterministic verification techniques that go beyond SMTP handshake checks, resolving the actual mailbox existence on catch-all domains. The result is a clear valid/invalid verdict instead of an inconclusive shrug.

Installation

Maven

<dependency>
    <groupId>io.enrow</groupId>
    <artifactId>catch-all-email-verifier</artifactId>
    <version>1.0.0</version>
</dependency>

Gradle

implementation 'io.enrow:catch-all-email-verifier:1.0.0'

Requires Java 11+. Only dependency: Gson.

Simple Usage

import io.enrow.catchallverifier.CatchAllVerifier;
import java.util.Map;

Map<String, Object> verification = CatchAllVerifier.verify("your_api_key", Map.of(
    "email", "tcook@apple.com"
));

Map<String, Object> result = CatchAllVerifier.get("your_api_key", (String) verification.get("id"));

System.out.println(result.get("email"));         // tcook@apple.com
System.out.println(result.get("qualification")); // valid

CatchAllVerifier.verify returns a verification ID. The verification runs asynchronously -- call CatchAllVerifier.get to retrieve the result once it is ready. You can also pass a webhook URL inside a settings map to get notified automatically.

Bulk verification

Map<String, Object> batch = CatchAllVerifier.verifyBulk("your_api_key", Map.of(
    "verifications", java.util.List.of(
        Map.of("email", "tcook@apple.com"),
        Map.of("email", "satya@microsoft.com"),
        Map.of("email", "jensen@nvidia.com")
    )
));

// batch.get("batchId"), batch.get("total"), batch.get("status")

Map<String, Object> results = CatchAllVerifier.getBulk("your_api_key", (String) batch.get("batchId"));
// results.get("results") -- list of result maps

Up to 5,000 verifications per batch. Pass a webhook URL inside settings to get notified when the batch completes.

Error handling

try {
    CatchAllVerifier.verify("bad_key", Map.of("email", "test@test.com"));
} catch (RuntimeException e) {
    // e.getMessage() contains the API error description
    // Common errors:
    // - "Invalid or missing API key" (401)
    // - "Your credit balance is insufficient." (402)
    // - "Rate limit exceeded" (429)
}

Getting an API key

Register at app.enrow.io to get your API key. You get 50 free credits (= 200 verifications) with no credit card required. Each verification costs 0.25 credits.

Paid plans start at $17/mo for 1,000 credits up to $497/mo for 100,000 credits. See pricing.

Documentation

• Enrow API documentation
• Full Enrow SDK -- includes email finder, phone finderand more

License

MIT -- see LICENSE for details.