[11.x] Document the fluent email Rule validation

validation.md

@@ -31,6 +31,7 @@
     - [Error Message Indexes and Positions](#error-message-indexes-and-positions)
 - [Validating Files](#validating-files)
 - [Validating Passwords](#validating-passwords)
+- [Validating Emails](#validating-emails)
 - [Custom Validation Rules](#custom-validation-rules)
     - [Using Rule Objects](#using-rule-objects)
     - [Using Closures](#using-closures)
@@ -1240,6 +1241,8 @@ The `filter` validator, which uses PHP's `filter_var` function, ships with Larav
 > [!WARNING]  
 > The `dns` and `spoof` validators require the PHP `intl` extension.
 
+Since email validation can be quite complex, you may use [Rule::email()](#validating-emails) to fluently construct the rule.
+
 <a name="rule-ends-with"></a>
 #### ends_with:_foo_,_bar_,...
 
@@ -2241,6 +2244,213 @@ Occasionally, you may want to attach additional validation rules to your default
         // ...
     });
 
+<a name="validating-emails"></a>
+## Validating Emails
+
+Laravel provides a variety of validation rules that may be used to validate uploaded files, such as `rfc`, `strict` and `dns`. While you are free to specify these rules individually when validating emails, Laravel also offers a fluent email validation rule builder that you may find convenient:
+To ensure that emails are valid according to your application's requirements, you may use `Rule` class to fluently define the rule via ` Rule::email()`:
+
+```php
+use Illuminate\Support\Facades\Validator;
+use Illuminate\Validation\Rule;
+
+$validator = Validator::make($request->all(), [
+    'email' => ['required', Rule::email()],
+]);
+```
+The `Email` rule object allows you to easily customize how emails are validated for your application, such as specifying that emails require RFC compliance, DNS checks, or spoof detection:
+
+```php
+// Basic RFC compliance...
+Rule::email()->rfcCompliant();
+
+// Strict RFC compliance...
+Rule::email()->rfcCompliant(strict: true);
+
+// Check for valid MX records...
+Rule::email()->validateMxRecord();
+
+// Prevent spoofing...
+Rule::email()->preventSpoofing();
+```
+Of course, you may chain all the methods in the examples above:
+
+```php
+Rule::email()
+    ->rfcCompliant(strict: true)
+    ->validateMxRecord()
+    ->preventSpoofing();
+```
+
+> [!WARNING]  
+> The `validateMxRecord()` and `preventSpoofing()` validators require the PHP `intl` extension.
+
+<a name="defining-default-email-rules"></a>
+#### Defining Default Email Rules
+You may find it convenient to specify the default validation rules for emails in a single location of your application. You can easily accomplish this using the Email::defaults method, which accepts a closure. The closure given to the defaults method should return the default configuration of the `Email` rule. Typically, the `defaults` rule should be called within the boot method of one of your application's service providers:
+
+```php
+use Illuminate\Validation\Rules\Email;
+
+/**
+ * Bootstrap any application services.
+ */
+public function boot(): void
+{
+    Email::defaults(function () {
+        $rule = (new Email())->rfcCompliant(strict: true)->preventSpoofing(),
+
+        return $this->app->isProduction()
+                    ? $rule->validateMxRecord()
+                    : $rule;
+    });
+}
+```
+Then, when you would like to apply the default rules to a particular email undergoing validation, you may invoke the defaults method with no arguments:
+
+```php
+'email' => ['required', Email::defaults()],
+```
+Occasionally, you may want to attach additional validation rules to your default email validation rules. You may use the rules method to accomplish this:
+
+```php
+Email::defaults(function () {
+    return (new Email())->rfcCompliant(strict: true)
+      ->preventSpoofing()
+      ->rules(['ends_with:@example.com']);
+});
+```
+
+<a name="email-validation-use-cases-examples"></a>
+### Use Cases & Examples
+
+Each method on the `Email` rule addresses a different aspect of email validation.
+
+<a name="rfc-compliant-email-validation"></a>
+#### `rfcCompliant(strict: bool)`
+
+**What it does**
+- Validates the email according to [RFC 5322](https://datatracker.ietf.org/doc/html/rfc5322).
+- Passing `true` enforces stricter RFC checks (e.g., rejects trailing dots or multiple consecutive dots).
+
+**When to use it**
+- Use `rfcCompliant()` for typical RFC validation while allowing some uncommon formats.
+- Use `rfcCompliant(strict: true)` to reject unusual but technically valid addresses.
+
+**Email addresses that pass on `rfcCompliant()` but fail on `rfcCompliant(strict: true)`**
+  - `test@example` (No TLD)
+  - `"has space"@example.com` (quoted local part with space)
+  - `name@[127.0.0.1]` (Local-part with domain-literal IPv4 address)
+  - `some(comment)@example.com` (Comment in local part)
+
+**Code sample**
+```php
+  // Basic RFC validation
+  Rule::email()->rfcCompliant();
+
+  // Strict RFC validation
+  Rule::email()->rfcCompliant(strict: true);
+```
+
+<a name="validate-mx-record-email-validation"></a>
+#### `validateMxRecord()`
+
+**What it does**
+- Ensures the domain has a valid MX record so it can receive mail.
+
+**When to use it**
+- Especially useful for sign-ups, password resets, or anywhere deliverability matters.
+
+> [!NOTE]
+> This rule triggers DNS lookups, which adds latency to the request and can fail if the domain’s DNS is temporarily unreachable.
+
+**Code sample**
+```php
+  Rule::email()->validateMxRecord();
+```
+
+<a name="prevent-spoofing-email-validation"></a>
+#### `preventSpoofing()`
+
+**What it does**
+- Detects homograph or deceptive Unicode usage (e.g., Cyrillic “р” vs. Latin “r”) to prevent phishing or impersonation.
+
+**When to use it**
+- Ideal in security-sensitive contexts or where email spoofing is a concern.
+
+**Code sample**  
+```php
+  Rule::email()->preventSpoofing();
+```
+
+> [!NOTE]
+> The `validateMxRecord()` and `preventSpoofing()` methods require the PHP `intl` extension.
+
+<a name="with-native-email-validation"></a>
+#### `withNativeValidation()`
+
+**What it does**
+- Uses PHP’s `FILTER_VALIDATE_EMAIL` for validation.
+- When `allowUnicode` is `true`, some Unicode characters are allowed.
+
+**When to use it**
+- If you want an additional layer of PHP’s built-in validation.
+- Typically for ASCII addresses unless you explicitly allow Unicode.
+
+**Email addresses that pass on `withNativeValidation()` but fail on `rfcCompliant(strict: true)`**
+- `abc."test"@example.com`
+- `name@[127.0.0.1]`
+- `"ab\\(c"@example.com`
+
+> [!NOTE]
+> `withNativeValidation()` is **less strict** than RFC validation and was previously the default in Laravel. If you need strict RFC compliance, use `rfcCompliant(strict: true)` instead.
+
+**Code sample**  
+```php
+  // Use native PHP validation (ASCII-only)
+  Rule::email()->withNativeValidation();
+
+  // Allow some Unicode
+  Rule::email()->withNativeValidation(allowUnicode: true);
+```
+
+<a name="email-validation-rule-matrix"></a>
+### Email Validation Rule Matrix
+
+Below is a single table showcasing different email address formats, highlighting whether each ✅ **passes** or ❌ **fails** the validation methods:
+
+| **Email Address**                    | **rfcCompliant()** | **rfcCompliant(strict: true)** | **withNativeValidation()** | **withNativeValidation(allowUnicode: true)** | **validateMxRecord()** | **preventSpoofing()** |
+|--------------------------------------|--------------------|--------------------------------|----------------------------|----------------------------------------------|------------------------|-----------------------|
+| `"has space"@example.com`            | ✅                  | ❌                              | ❌                          | ❌                                            | ✅                      | ✅                     |
+| `abc."test"@example.com`             | ✅                  | ❌                              | ✅                          | ✅                                            | ✅                      | ✅                     |
+| `"ab\\(c"@example.com`               | ✅                  | ❌                              | ✅                          | ✅                                            | ✅                      | ✅                     |
+| `name@[127.0.0.1]`                   | ✅                  | ❌                              | ✅                          | ✅                                            | ✅                      | ✅                     |
+| `test@example` <br>(no TLD)          | ✅                  | ❌                              | ❌                          | ❌                                            | ❌                      | ✅                     |
+| `test@localhost` <br>(no TLD)        | ✅                  | ❌                              | ❌                          | ❌                                            | ❌                      | ✅                     |
+| `[email protected]`           | ✅                  | ✅                              | ✅                          | ✅                                            | ✅                      | ✅                     |
+| `té[email protected]`                   | ✅                  | ✅                              | ❌                          | ✅                                            | ✅                      | ✅                     |
+| `user@üñîçødé.com`                   | ✅                  | ✅                              | ❌                          | ❌                                            | ✅                      | ✅                     |
+| `admin@examрle.com` <br>(Cyrillic р) | ✅                  | ✅                              | ✅                          | ✅                                            | ✅                      | ❌                     |
+| `admin@exam<U+0440>le.com`           | ✅                  | ✅                              | ✅                          | ✅                                            | ✅                      | ❌                     |
+| `test@@example.com`                  | ❌                  | ❌                              | ❌                          | ❌                                            | ❌                      | ❌                     |
+
+<a name="combining-email-validation-methods"></a>
+### Combining Methods
+
+You can **chain** multiple methods to cover various scenarios:
+
+```php
+  $validator = Validator::make($request->all(), [
+      'email' => [
+          'required',
+          Rule::email()
+              ->rfcCompliant(strict: true)  // Strict RFC validation
+              ->validateMxRecord()          // Requires valid MX record
+              ->preventSpoofing()           // Detects homograph attacks
+      ],
+  ]);
+```
+
 <a name="custom-validation-rules"></a>
 ## Custom Validation Rules