A work-email validation rule for Laravel

Laravel’s validation rules are the natural place for this: 'email' => ['required', 'email', new WorkEmail].

1. Config

// config/services.php
'isbusinessemail' => [
    'key' => env('IBE_API_KEY'),
],

# .env
IBE_API_KEY=ibe_live_…

2. The rule

php artisan make:rule WorkEmail

<?php

namespace App\Rules;

use Closure;
use Illuminate\Contracts\Validation\ValidationRule;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Throwable;

class WorkEmail implements ValidationRule
{
    public ?array $verdict = null;

    public function __construct(private string $policy = 'b2b') {}

    public function validate(string $attribute, mixed $value, Closure $fail): void
    {
        try {
            $response = Http::withToken(config('services.isbusinessemail.key'))
                ->acceptJson()
                ->connectTimeout(2)
                ->timeout(3)
                ->post('https://api.isbusinessemail.com/v1/check', [
                    'email' => $value,
                    'policy' => $this->policy,
                ]);
        } catch (Throwable $e) {
            Log::warning('isBusinessEmail unreachable', ['error' => $e->getMessage()]);
            return; // fail open
        }

        if (! $response->successful()) {
            Log::warning('isBusinessEmail error', ['status' => $response->status()]);
            return; // fail open
        }

        $this->verdict = $response->json();

        if (($this->verdict['recommendation'] ?? 'allow') === 'block') {
            $suggestion = $this->verdict['did_you_mean'] ?? null;
            $fail($suggestion
                ? "Please use your work email. Did you mean {$suggestion}?"
                : 'Please use your work email.');
        }
    }
}

3. Use it

use App\Rules\WorkEmail;

public function store(Request $request)
{
    $rule = new WorkEmail();

    $data = $request->validate([
        'name'  => ['required', 'string', 'max:255'],
        'email' => ['required', 'email', 'max:254', $rule],
    ]);

    $user = User::create([
        'name' => $data['name'],
        'email' => $data['email'],
        'email_category' => $rule->verdict['category'] ?? null,
        'needs_review' => ($rule->verdict['recommendation'] ?? 'review') === 'review',
    ]);

    // ...
}

Keeping a reference to the rule lets you store category and Workspace/Microsoft 365 detection without a second call.

Notes

• Put the cheap email rule before WorkEmail so obviously malformed input never costs a check.
• For policy: 'strict', use new WorkEmail('strict').
• In tests, Http::fake() lets you simulate allow, block and timeouts; or call the real API with test addresses.

Official docs: Laravel documentation (Validation, HTTP Client). See also: Signup form guide.