diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09ad17e..60f2e8c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,7 +4,7 @@ Yii Framework 2 swiftmailer extension Change Log
 2.0.7 under development
 -----------------------
 
-- no changes in this release.
+- Enh #37: `yii\swiftmailer\Logger` now chooses logging level depending on incoming entry format (klimov-paul)
 
 
 2.0.6 September 09, 2016
diff --git a/Logger.php b/Logger.php
index d0c0e05..c404822 100644
--- a/Logger.php
+++ b/Logger.php
@@ -37,7 +37,25 @@ class Logger implements \Swift_Plugins_Logger
      */
     public function add($entry)
     {
-        Yii::info($entry, __METHOD__);
+        $categoryPrefix = substr($entry, 0, 2);
+        switch ($categoryPrefix) {
+            case '++':
+                $level = \yii\log\Logger::LEVEL_TRACE;
+                break;
+            case '>>':
+            case '<<':
+                $level = \yii\log\Logger::LEVEL_INFO;
+                break;
+            case '!!':
+                $level = \yii\log\Logger::LEVEL_WARNING;
+                break;
+        }
+
+        if (!isset($level)) {
+            $level = \yii\log\Logger::LEVEL_INFO;
+        }
+
+        Yii::getLogger()->log($entry, $level, __METHOD__);
     }
 
     /**
diff --git a/tests/LoggerTest.php b/tests/LoggerTest.php
new file mode 100644
index 0000000..9a36ddf
--- /dev/null
+++ b/tests/LoggerTest.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace yiiunit\extensions\swiftmailer;
+
+use Yii;
+use yii\swiftmailer\Logger;
+
+class LoggerTest extends TestCase
+{
+    protected function getLastLogMessage()
+    {
+        return end(Yii::getLogger()->messages);
+    }
+
+    /**
+     * Data provider for [[testAdd()]]
+     * @return array test data
+     */
+    public function dataProviderAdd()
+    {
+        return [
+            [
+                '>> command sent',
+                [
+                    'message' => '>> command sent',
+                    'level' => \yii\log\Logger::LEVEL_INFO,
+                ]
+            ],
+            [
+                '<< response received',
+                [
+                    'message' => '<< response received',
+                    'level' => \yii\log\Logger::LEVEL_INFO,
+                ]
+            ],
+            [
+                '++ transport started',
+                [
+                    'message' => '++ transport started',
+                    'level' => \yii\log\Logger::LEVEL_TRACE,
+                ]
+            ],
+            [
+                '!! error message',
+                [
+                    'message' => '!! error message',
+                    'level' => \yii\log\Logger::LEVEL_WARNING,
+                ]
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider dataProviderAdd
+     *
+     * @param string $entry
+     * @param array $expectedLogMessage
+     */
+    public function testAdd($entry, array $expectedLogMessage)
+    {
+        $logger = new Logger();
+
+        $logger->add($entry);
+
+        $logMessage = $this->getLastLogMessage();
+
+        $this->assertEquals($expectedLogMessage['message'], $logMessage[0]);
+        $this->assertEquals($expectedLogMessage['level'], $logMessage[1]);
+    }
+}
\ No newline at end of file
diff --git a/tests/MailerTest.php b/tests/MailerTest.php
index 13e9509..56cafbe 100644
--- a/tests/MailerTest.php
+++ b/tests/MailerTest.php
@@ -7,11 +7,6 @@ use yii\swiftmailer\Mailer;
 
 Yii::setAlias('@yii/swiftmailer', __DIR__ . '/../../../../extensions/swiftmailer');
 
-/**
- * @group vendor
- * @group mail
- * @group swiftmailer
- */
 class MailerTest extends TestCase
 {
     public function setUp()