Add tag support to EmailEndpoint

src/Endpoints/EmailEndpoint.php

@@ -183,6 +183,18 @@ public function metadata(array $metadata): self
         return $this;
     }
 
+    /**
+     * Set the tag of the email.
+     *
+     * @param  string|null  $tag  The tag formatted as slug
+     */
+    public function tag(?string $tag): self
+    {
+        $this->payload['tag'] = $tag;
+
+        return $this;
+    }
+
     /**
      * Send the composed email using the current payload.
      *

tests/Endpoints/EmailEndpointTest.php

@@ -253,3 +253,23 @@
         ->metadata(['foo' => 'bar'])
         ->send();
 });
+
+test('it handles tags', function () {
+    $this->httpClient
+        ->shouldReceive('post')
+        ->once()
+        ->with('/v1/send', [
+            'from' => 'sender@example.com',
+            'to' => ['recipient@example.com'],
+            'subject' => 'Test Subject',
+            'tag' => 'campaign',
+        ], [])
+        ->andReturn(['message_id' => '123', 'status' => 'pending']);
+
+    $this->endpoint
+        ->from('sender@example.com')
+        ->to('recipient@example.com')
+        ->subject('Test Subject')
+        ->tag('campaign')
+        ->send();
+});