diff --git a/composer.json b/composer.json
index 9ca7c65..6fcb663 100644
--- a/composer.json
+++ b/composer.json
@@ -1,40 +1,40 @@
-{
-    "name": "synergitech/laravel-postal",
-    "description": "This library integrates Postal with the standard Laravel mail framework.",
-    "keywords": [
-        "Laravel",
-        "Postal",
-        "Email"
-    ],
-    "homepage": "https://github.com/synergitech/laravel-postal",
-    "license": "MIT",
-    "require": {
-        "php": "^8.0",
-        "laravel/framework": "^9.0.1|^10.0",
-        "postal/postal": "^1.0.1"
-    },
-    "require-dev": {
-        "phpunit/phpunit": "^9.0",
-        "orchestra/testbench": "^7.0|^8.0",
-        "nunomaduro/larastan": "^2.0"
-    },
-    "autoload": {
-        "psr-4": {
-            "SynergiTech\\Postal\\": "src",
-            "SynergiTech\\Postal\\Tests\\": "tests"
-        }
-    },
-    "extra": {
-        "laravel": {
-            "providers": [
-                "SynergiTech\\Postal\\PostalServiceProvider"
-            ]
-        }
-    },
-    "scripts": {
-        "test": [
-            "phpunit",
-            "phpstan --memory-limit=1G"
-        ]
-    }
-}
+{
+    "name": "synergitech/laravel-postal",
+    "description": "This library integrates Postal with the standard Laravel mail framework.",
+    "keywords": [
+        "Laravel",
+        "Postal",
+        "Email"
+    ],
+    "homepage": "https://github.com/synergitech/laravel-postal",
+    "license": "MIT",
+    "require": {
+        "php": "^8.0",
+        "laravel/framework": "^9.0.1|^10.0",
+        "postal/postal": "^2.0"
+    },
+    "require-dev": {
+        "phpunit/phpunit": "^9.0",
+        "orchestra/testbench": "^7.0|^8.0",
+        "nunomaduro/larastan": "^2.0"
+    },
+    "autoload": {
+        "psr-4": {
+            "SynergiTech\\Postal\\": "src",
+            "SynergiTech\\Postal\\Tests\\": "tests"
+        }
+    },
+    "extra": {
+        "laravel": {
+            "providers": [
+                "SynergiTech\\Postal\\PostalServiceProvider"
+            ]
+        }
+    },
+    "scripts": {
+        "test": [
+            "phpunit",
+            "phpstan --memory-limit=1G"
+        ]
+    }
+}
diff --git a/phpstan-baseline.neon b/phpstan-baseline.neon
index 118b5e9..0c47944 100644
--- a/phpstan-baseline.neon
+++ b/phpstan-baseline.neon
@@ -35,11 +35,6 @@ parameters:
 			count: 1
 			path: src/PostalNotificationChannel.php
 
-		-
-			message: "#^Access to an undefined property Postal\\\\SendResult\\:\\:\\$result\\.$#"
-			count: 1
-			path: src/PostalTransport.php
-
 		-
 			message: "#^Access to an undefined property object\\:\\:\\$body\\.$#"
 			count: 2
@@ -95,3 +90,12 @@ parameters:
 			count: 1
 			path: src/PostalTransport.php
 
+		-
+			message: "#^Parameter \\#1 \\$content of method Postal\\\\Send\\\\Message\\:\\:htmlBody\\(\\) expects string, resource\\|string given\\.$#"
+			count: 1
+			path: src/PostalTransport.php
+
+		-
+			message: "#^Parameter \\#1 \\$content of method Postal\\\\Send\\\\Message\\:\\:plainBody\\(\\) expects string, resource\\|string given\\.$#"
+			count: 1
+			path: src/PostalTransport.php
diff --git a/src/PostalNotificationChannel.php b/src/PostalNotificationChannel.php
index dfc731c..8c2e59d 100644
--- a/src/PostalNotificationChannel.php
+++ b/src/PostalNotificationChannel.php
@@ -13,7 +13,7 @@ class PostalNotificationChannel extends MailChannel
      *
      * @param  mixed  $notifiable
      * @param  \Illuminate\Notifications\Notification  $notification
-     * @return void
+     * @return \Illuminate\Mail\SentMessage|null
      */
     public function send($notifiable, Notification $notification)
     {
diff --git a/src/PostalServiceProvider.php b/src/PostalServiceProvider.php
index c06b62a..3140183 100644
--- a/src/PostalServiceProvider.php
+++ b/src/PostalServiceProvider.php
@@ -31,12 +31,19 @@ public function boot(): void
         }
 
         Mail::extend('postal', function (array $config = []) {
-            $config = config('postal', []);
+            $config = config('postal');
+
             if (! is_array($config)) {
-                $config = [];
+                throw new \RuntimeException('missing Postal configuration');
+            }
+            if (! is_string($config['domain'])) {
+                throw new \RuntimeException('missing Postal domain configuration');
+            }
+            if (! is_string($config['key'])) {
+                throw new \RuntimeException('missing Postal key configuration');
             }
 
-            return new PostalTransport(new Client($config['domain'] ?? null, $config['key'] ?? null));
+            return new PostalTransport(new Client($config['domain'], $config['key']));
         });
     }
 }
diff --git a/src/PostalTransport.php b/src/PostalTransport.php
index bb80bd6..d130844 100644
--- a/src/PostalTransport.php
+++ b/src/PostalTransport.php
@@ -2,12 +2,10 @@
 
 namespace SynergiTech\Postal;
 
-use Illuminate\Database\Eloquent\Model;
-use Illuminate\Support\Facades\DB;
 use Postal\Client;
-use Postal\Error;
-use Postal\SendMessage;
-use Postal\SendResult;
+use Postal\ApiException;
+use Postal\Send\Message as SendMessage;
+use Postal\Send\Result as SendResult;
 use Symfony\Component\Mailer\Exception\TransportException;
 use Symfony\Component\Mailer\SentMessage;
 use Symfony\Component\Mailer\Transport\AbstractTransport;
@@ -37,8 +35,8 @@ protected function doSend(SentMessage $sentMessage): void
         $postalmessage = $this->symfonyToPostal($symfonyMessage);
 
         try {
-            $response = $postalmessage->send();
-        } catch (Error $error) {
+            $response = $this->client->send->message($postalmessage);
+        } catch (ApiException $error) {
             throw new TransportException($error->getMessage(), $error->getCode(), $error);
         }
 
@@ -46,7 +44,7 @@ protected function doSend(SentMessage $sentMessage): void
 
         // send known header back for laravel to match emails coming out of Postal
         // - doesn't seem we can replace Message-ID
-        $headers->addTextHeader('Postal-Message-ID', $response->result->message_id);
+        $headers->addTextHeader('Postal-Message-ID', $response->message_id);
 
         if (config('postal.enable.emaillogging') !== true) {
             return;
@@ -61,7 +59,7 @@ protected function doSend(SentMessage $sentMessage): void
         if ($emailable_type != '' && $emailable_id != '') {
             $emailmodel = config('postal.models.email');
             \DB::table((new $emailmodel)->getTable())
-                ->where('postal_email_id', $response->result->message_id)
+                ->where('postal_email_id', $response->message_id)
                 ->update([
                     'emailable_type' => $emailable_type,
                     'emailable_id' => $emailable_id,
@@ -107,13 +105,13 @@ private function symfonyToPostal(Email $symfonyMessage): SendMessage
             $postalMessage->htmlBody($symfonyMessage->getHtmlBody());
         }
 
-        foreach ($symfonyMessage->getAttachments() as $symfonyPart) {
+        foreach ($symfonyMessage->getAttachments() as $index => $symfonyPart) {
             $filename = $symfonyPart
                 ->getPreparedHeaders()
                 ->getHeaderParameter('content-disposition', 'filename');
 
             $postalMessage->attach(
-                $filename,
+                $filename ?? "attached_file_$index",
                 $symfonyPart->getMediaType() . '/' . $symfonyPart->getMediaSubtype(),
                 $symfonyPart->getBody()
             );
@@ -162,9 +160,9 @@ private function recordEmailsFromResponse(Email $symfonyMessage, SendResult $res
                 $email->body = $symfonyMessage->getHtmlBody();
             }
 
-            $email->postal_email_id = $response->result->message_id;
-            $email->postal_id = $message->id();
-            $email->postal_token = $message->token();
+            $email->postal_email_id = $response->message_id;
+            $email->postal_id = $message->id;
+            $email->postal_token = $message->token;
 
             $email->save();
         }
@@ -181,7 +179,7 @@ private function stringifyAddress(Address $address): string
 
     private function getNewSendMessage(): SendMessage
     {
-        return new SendMessage($this->client);
+        return new SendMessage();
     }
 
     /**
diff --git a/tests/FeatureTest.php b/tests/FeatureTest.php
index 601fa3a..8bf241c 100644
--- a/tests/FeatureTest.php
+++ b/tests/FeatureTest.php
@@ -5,6 +5,8 @@
 use Illuminate\Support\Facades\Mail;
 use Illuminate\Support\Facades\Notification;
 use Postal\Client;
+use Postal\Send\Result;
+use Postal\SendService;
 use Symfony\Component\Mailer\DelayedEnvelope;
 use SynergiTech\Postal\PostalNotificationChannel;
 use SynergiTech\Postal\PostalTransport;
@@ -13,19 +15,23 @@ class FeatureTest extends TestCase
 {
     public function testSendingNotificationOnDemand()
     {
-        $result = new \stdClass;
-        $result->message_id = 'feature-test';
-        $message = new \stdClass();
-        $message->id = 'feature-test';
-        $message->token = 'feature-test';
-        $result->messages['feature-test@example.com'] = $message;
-
-        $clientMock = $this->createMock(Client::class);
-        $clientMock
-            ->method('makeRequest')
-            ->willReturn($result);
-
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->createMock(SendService::class);
+
+            $result = new Result([
+                'message_id' => 'feature-test',
+                'messages' => ['feature-test@example.com' => [
+                    'id' => 123,
+                    'token' => 'feature-test',
+                ]],
+            ]);
+
+            $serviceMock->method('message')
+                ->willReturn($result);
+
+            $clientMock->send = $serviceMock;
+
             return new PostalTransport($clientMock);
         });
 
@@ -48,19 +54,23 @@ public function testSendingNotificationOnDemand()
 
     public function testSendingNotificationOnDemandWithAlias()
     {
-        $result = new \stdClass;
-        $result->message_id = 'feature-test';
-        $message = new \stdClass();
-        $message->id = 'feature-test';
-        $message->token = 'feature-test';
-        $result->messages['feature-test@example.com'] = $message;
-
-        $clientMock = $this->createMock(Client::class);
-        $clientMock
-            ->method('makeRequest')
-            ->willReturn($result);
-
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->createMock(SendService::class);
+
+            $result = new Result([
+                'message_id' => 'feature-test',
+                'messages' => ['feature-test@example.com' => [
+                    'id' => 123,
+                    'token' => 'feature-test',
+                ]],
+            ]);
+
+            $serviceMock->method('message')
+                ->willReturn($result);
+
+            $clientMock->send = $serviceMock;
+
             return new PostalTransport($clientMock);
         });
 
@@ -83,19 +93,23 @@ public function testSendingNotificationOnDemandWithAlias()
 
     public function testSendingNotificationWithNotifiableTrait()
     {
-        $result = new \stdClass;
-        $result->message_id = 'feature-test';
-        $message = new \stdClass();
-        $message->id = 'feature-test';
-        $message->token = 'feature-test';
-        $result->messages['feature-test@example.com'] = $message;
-
-        $clientMock = $this->createMock(Client::class);
-        $clientMock
-            ->method('makeRequest')
-            ->willReturn($result);
-
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->createMock(SendService::class);
+
+            $result = new Result([
+                'message_id' => 'feature-test',
+                'messages' => ['feature-test@example.com' => [
+                    'id' => 123,
+                    'token' => 'feature-test',
+                ]],
+            ]);
+
+            $serviceMock->method('message')
+                ->willReturn($result);
+
+            $clientMock->send = $serviceMock;
+
             return new PostalTransport($clientMock);
         });
 
diff --git a/tests/PostalServiceProviderTest.php b/tests/PostalServiceProviderTest.php
index 156a90f..2222c0f 100644
--- a/tests/PostalServiceProviderTest.php
+++ b/tests/PostalServiceProviderTest.php
@@ -10,6 +10,10 @@ public function testBoot()
     {
         // assert the service provider did boot and extend the mail
 
+        config([
+            'postal' => ['domain' => 'example.com', 'key' => 'hunter2'],
+        ]);
+
         $driver = app('mail.manager')
             ->createSymfonyTransport(config('mail.mailers.postal'));
 
diff --git a/tests/PostalTransportTest.php b/tests/PostalTransportTest.php
index d92804e..58e43e7 100644
--- a/tests/PostalTransportTest.php
+++ b/tests/PostalTransportTest.php
@@ -5,7 +5,10 @@
 use Illuminate\Support\Facades\Mail;
 use Mockery\MockInterface;
 use Postal\Client;
-use Postal\Error;
+use Postal\ApiException;
+use Postal\Send\Message;
+use Postal\Send\Result;
+use Postal\SendService;
 use Symfony\Component\Mailer\Exception\TransportException;
 use SynergiTech\Postal\PostalTransport;
 
@@ -13,18 +16,18 @@ class PostalTransportTest extends TestCase
 {
     public function testSendPostalFailure(): void
     {
-        // requests requires a URL
-        config(['postal.domain' => 'http://example.com']);
-
-        // the transport converts Postal\Error to TransportException
+        // the transport converts Postal\ApiException to TransportException
         $this->expectException(TransportException::class);
 
-        $clientMock = $this->createMock(Client::class);
-        $clientMock
-            ->method('makeRequest')
-            ->will($this->throwException(new Error()));
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->createMock(SendService::class);
+
+            $serviceMock->method('message')
+                ->will($this->throwException(new ApiException()));
+
+            $clientMock->send = $serviceMock;
 
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
             return new PostalTransport($clientMock);
         });
 
@@ -33,20 +36,23 @@ public function testSendPostalFailure(): void
 
     public function testSendSuccess(): void
     {
-        // requests requires a URL
-        config(['postal.domain' => 'http://example.com']);
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->createMock(SendService::class);
+
+            $result = new Result([
+                'message_id' => 'test',
+                'messages' => ['testsendsuccess@example.com' => [
+                    'id' => 123,
+                    'token' => 'first',
+                ]],
+            ]);
 
-        $clientMock = $this->createMock(Client::class);
-        $result = new \stdClass;
-        $result->message_id = 'test';
-        $message = new \stdClass();
-        $message->id = 'first';
-        $message->token = 'first';
-        $result->messages['testsendsuccess@example.com'] = $message;
+            $serviceMock->method('message')
+                ->willReturn($result);
 
-        $clientMock->method('makeRequest')->willReturn((object)$result);
+            $clientMock->send = $serviceMock;
 
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
             return new PostalTransport($clientMock);
         });
 
@@ -64,19 +70,23 @@ public function testSendSuccess(): void
 
     public function testPostalCaseSensitivity(): void
     {
-        $result = new \stdClass;
-        $result->message_id = 'caseSensitivityTest';
-        $message = new \stdClass();
-        $message->id = 'caseSensitivityTest';
-        $message->token = 'caseSensitivityTest';
-        $result->messages['caseSensitivityTest@example.com'] = $message;
-
-        $clientMock = $this->createMock(Client::class);
-        $clientMock
-            ->method('makeRequest')
-            ->willReturn($result);
-
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->createMock(SendService::class);
+
+            $result = new Result([
+                'message_id' => 'caseSensitivityTest',
+                'messages' => ['caseSensitivityTest@example.com' => [
+                    'id' => 123,
+                    'token' => 'caseSensitivityTest',
+                ]],
+            ]);
+
+            $serviceMock->method('message')
+                ->willReturn($result);
+
+            $clientMock->send = $serviceMock;
+
             return new PostalTransport($clientMock);
         });
 
@@ -93,29 +103,28 @@ public function testPostalCaseSensitivity(): void
 
     public function testAttachments(): void
     {
-        // requests requires a URL
-        config(['postal.domain' => 'http://example.com']);
-
-        $clientMock = $this->mock(Client::class, function (MockInterface $mock) {
-            $message = new \stdClass();
-            $message->id = 'first';
-            $message->token = 'first';
-
-            $result = new \stdClass;
-            $result->message_id = 'test';
-            $result->messages['testsendsuccess@example.com'] = $message;
-
-            $mock->shouldReceive('makeRequest')
-                ->withArgs(function ($controller, $action, $parameters) {
-                    $this->assertCount(1, $parameters['attachments']);
-                    $this->assertSame('test-attachment', $parameters['attachments'][0]['name']);
-
-                    return $controller == 'send' && $action == 'message';
+        Mail::extend('postal', function (array $config = []) {
+            $clientMock = $this->createMock(Client::class);
+            $serviceMock = $this->mock(SendService::class);
+
+            $result = new Result([
+                'message_id' => 'first',
+                'messages' => ['testsendsuccess@example.com' => [
+                    'id' => 123,
+                    'token' => 'first',
+                ]],
+            ]);
+
+            $serviceMock->shouldReceive('message')
+                ->withArgs(function (Message $message) {
+                    $this->assertCount(1, $message->attachments);
+
+                    return $message->attachments[0]['name'] == 'test-attachment';
                 })
-                ->andReturn((object)$result);
-        });
+                ->andReturn($result);
+
+            $clientMock->send = $serviceMock;
 
-        Mail::extend('postal', function (array $config = []) use ($clientMock) {
             return new PostalTransport($clientMock);
         });