diff --git a/src/Openbuildings/Postmark/Api.php b/src/Openbuildings/Postmark/Api.php
index 6ee73ed..89863eb 100644
--- a/src/Openbuildings/Postmark/Api.php
+++ b/src/Openbuildings/Postmark/Api.php
@@ -14,8 +14,11 @@ class Api
 {
     const SEND_URI = 'http://api.postmarkapp.com/email';
 
+    const SEND_URI_SECURE = 'https://api.postmarkapp.com/email';
+
     protected $_token;
 
+    protected $secure = true;
 
     public function __construct($token = null)
     {
@@ -70,7 +73,7 @@ public function send(array $data)
         curl_setopt_array(
             $curl,
             array(
-                CURLOPT_URL => static::SEND_URI,
+                CURLOPT_URL => $this->get_send_uri(),
                 CURLOPT_POST => true,
                 CURLOPT_HTTPHEADER => $this->headers(),
                 CURLOPT_POSTFIELDS => json_encode($data),
@@ -81,7 +84,8 @@ public function send(array $data)
         $response = curl_exec($curl);
 
         if (!$response) {
-            throw new \Exception('Postmark delivery failed: ' . curl_error($curl));
+            $curl_error = curl_error($curl) ?: 'unknown cURL error';
+            throw new \Exception('Postmark delivery failed: ' . $curl_error);
         }
 
         $response = @json_decode($response, true);
@@ -101,4 +105,28 @@ public function send(array $data)
 
         return $response;
     }
+
+    public function is_secure()
+    {
+        return $this->secure;
+    }
+
+    public function set_secure($secure)
+    {
+        $this->secure = $secure;
+
+        return $this;
+    }
+
+    public function get_send_uri()
+    {
+        if ($this->is_secure())
+        {
+            return static::SEND_URI_SECURE;
+        }
+        else
+        {
+            return static::SEND_URI;
+        }
+    }
 }
diff --git a/tests/src/ApiTest.php b/tests/src/ApiTest.php
index 384b336..5a25a7f 100644
--- a/tests/src/ApiTest.php
+++ b/tests/src/ApiTest.php
@@ -3,7 +3,6 @@
 namespace Openbuildings\Postmark\Test;
 
 use Openbuildings\Postmark\Api;
-use Openbuildings\Postmark\Test\Mock;
 use PHPUnit_Framework_TestCase;
 
 /**
@@ -147,4 +146,86 @@ public function test_send()
             )
         );
     }
+
+    /**
+     * @covers Openbuildings\Postmark\Api::is_secure
+     */
+    public function test_is_secure()
+    {
+        $api = new Api();
+        $this->assertTrue($api->is_secure());
+
+        $api->set_secure(false);
+        $this->assertFalse($api->is_secure());
+
+        $api->set_secure(true);
+        $this->assertTrue($api->is_secure());
+    }
+
+    /**
+     * @covers Openbuildings\Postmark\Api::set_secure
+     */
+    public function test_set_secure()
+    {
+        $api = new Api();
+        $this->assertSame($api, $api->set_secure(false));
+        $this->assertFalse($api->is_secure());
+
+        $api->set_secure(true);
+        $this->assertTrue($api->is_secure());
+    }
+
+    /**
+     * @covers Openbuildings\Postmark\Api::get_send_uri
+     */
+    public function test_get_send_uri()
+    {
+        $api = new Api();
+        $this->assertEquals(Api::SEND_URI_SECURE, $api->get_send_uri());
+
+        $api->set_secure(false);
+        $this->assertEquals(Api::SEND_URI, $api->get_send_uri());
+
+        $api->set_secure(true);
+        $this->assertEquals(Api::SEND_URI_SECURE, $api->get_send_uri());
+    }
+
+    /**
+     * @covers Openbuildings\Postmark\Api::send
+     */
+    public function test_send_wrong_json()
+    {
+        $api_mock = $this->getMock(
+            'Openbuildings\Postmark\Api',
+            array(
+                'get_send_uri'
+            ),
+            array(
+                'POSTMARK_API_TEST'
+            )
+        );
+
+        $path_to_wrong_json = 'file://'.realpath(__DIR__.'/../test_data/wrong-json.json');
+
+        $api_mock
+            ->expects($this->once())
+            ->method('get_send_uri')
+            ->will($this->returnValue($path_to_wrong_json));
+
+        $this->setExpectedException(
+            'Exception',
+            'Postmark delivery failed: wrong json response'
+        );
+
+        $response = $api_mock->send(
+            array(
+                'From' => 'Mark Smith <support@example.com>',
+                'To' => 'test_email@example.com,test_email2@example.com,test_email3@example.com',
+                'Subject' => 'Test',
+                'HtmlBody' => '<b>Hello</b>',
+                'TextBody' => 'Hello',
+                'ReplyTo' => 'reply@example.com',
+            )
+        );
+    }
 }
diff --git a/tests/test_data/wrong-json.json b/tests/test_data/wrong-json.json
new file mode 100644
index 0000000..54f775c
--- /dev/null
+++ b/tests/test_data/wrong-json.json
@@ -0,0 +1 @@
+{'["}