Soenneker.Validators.Email.Disposable.Online 4.0.5457

Soenneker.Validators.Email.Disposable.Online

Downloads a disposable-domain list once and checks email domains against it without sending email addresses to the source.

Install

dotnet add package Soenneker.Validators.Email.Disposable.Online

Registration

using Soenneker.Validators.Email.Disposable.Online.Registrars;
using Microsoft.Extensions.DependencyInjection;

services.AddEmailDisposableOnlineValidatorAsSingleton();

Only singleton registration is provided. The validator owns one lazily initialized domain set and a named client entry in the shared HTTP client cache.

Configure the list source

{
  "Validators": {
    "Email": {
      "Disposable": {
        "Uri": "https://example.test/disposable-domains.json"
      }
    }
  }
}

The endpoint must return a JSON array of domain strings. When the setting is absent, the validator uses the disposable/disposable-email-domains domains.json file on GitHub. The URI is application configuration and should not be populated directly from request input.

Warm up and validate

using Soenneker.Validators.Email.Disposable.Online.Abstract;

await validator.WarmUp(cancellationToken);

bool? accepted = await validator.Validate(
    "person@example.com",
    cancellationToken);

Warm-up is optional; the first validation downloads the same data if needed. The download is cached for the lifetime of the validator and is not periodically refreshed.

Results have three states:

• false: the extracted domain is in the downloaded list;
• true: the domain is not listed, or the input has no extractable domain;
• null: the endpoint returned an empty domain list.

Domain matching is ordinal and case-insensitive. It is an exact lookup: listed parent domains do not automatically match subdomains. The utility extracts text after the last @; it does not validate email syntax, trim input, normalize internationalized domains, or verify deliverability. Use a syntax validator before this one when malformed input must be rejected.

Network and failure behavior

The list request is retried three times after the initial attempt. HTTP failures, non-success responses after retries, invalid JSON, cancellation, and unexpected response shapes propagate rather than returning null. A true result means only that the domain was absent from this downloaded snapshot.

The configured list service receives only a GET for its domain data; email addresses are not sent to it. The validator no longer includes the checked address in its empty-list warning.

Disposal removes the validator's named client entry from the shared client cache and disposes the lazy domain holder. Let dependency injection dispose the singleton at application shutdown.