diff --git a/.env.example b/.env.example
index 657a825..80d892f 100644
--- a/.env.example
+++ b/.env.example
@@ -35,3 +35,5 @@ SENDMAIL_DSN=sendmail://default
 MAILER_DSN=native://default
 
 MAIL_CHARSET=utf-8
+
+MAX_ATTEMPTS_DEFAULT=3
diff --git a/config/mailer.php b/config/mailer.php
index e76f14b..a0c04a2 100644
--- a/config/mailer.php
+++ b/config/mailer.php
@@ -65,5 +65,6 @@
             'dsn' => $_ENV['MAIL_DSN']
         ]
     ],
-    'mail-charset' => $_ENV['MAIL_CHARSET'] ?: 'utf-8'
+    'mail-charset' => $_ENV['MAIL_CHARSET'] ?: 'utf-8',
+    'max-attempts' => $_ENV['MAX_ATTEMPTS_DEFAULT']
 ];
diff --git a/src/Queue/Backend/Beanstalkd/BeanstalkdQueueStoreAdapter.php b/src/Queue/Backend/Beanstalkd/BeanstalkdQueueStoreAdapter.php
index 940f37c..cc99059 100644
--- a/src/Queue/Backend/Beanstalkd/BeanstalkdQueueStoreAdapter.php
+++ b/src/Queue/Backend/Beanstalkd/BeanstalkdQueueStoreAdapter.php
@@ -3,6 +3,7 @@
 namespace Da\Mailer\Queue\Backend\Beanstalkd;
 
 use Da\Mailer\Exception\InvalidCallException;
+use Da\Mailer\Helper\ConfigReader;
 use Da\Mailer\Queue\Backend\MailJobInterface;
 use Da\Mailer\Queue\Backend\QueueStoreAdapterInterface;
 use Pheanstalk\Job as PheanstalkJob;
@@ -107,21 +108,22 @@ public function dequeue()
      */
     public function ack(MailJobInterface $mailJob)
     {
+        $config = self::getConfig();
         if ($mailJob->isNewRecord()) {
             throw new InvalidCallException('BeanstalkdMailJob cannot be a new object to be acknowledged');
         }
 
         $pheanstalk = $this->getConnection()->getInstance()->useTube($this->queueName);
-        if ($mailJob->isCompleted()) {
+        $mailJob->incrementAttempt();
+
+        if($mailJob->isCompleted() || $mailJob->getAttempt() > $config['max-attempts']) {
+
             $pheanstalk->delete($mailJob->getPheanstalkJob());
             return null;
         }
 
-        $timestamp = $mailJob->getTimeToSend();
-        $delay = max(0, $timestamp - time());
-// add back to the queue as it wasn't completed maybe due to some transitory error
-        // could also be failed.
-        $pheanstalk->release($mailJob->getPheanstalkJob(), Pheanstalk::DEFAULT_PRIORITY, $delay);
+        $pheanstalk->release($mailJob->getPheanstalkJob());
+
         return null;
     }
 
@@ -150,4 +152,10 @@ protected function createPayload(MailJobInterface $mailJob)
                 'message' => $mailJob->getMessage(),
             ]);
     }
+
+    protected static function getConfig()
+    {
+        return ConfigReader::get();
+    }
+
 }
diff --git a/src/Queue/Backend/Pdo/PdoQueueStoreAdapter.php b/src/Queue/Backend/Pdo/PdoQueueStoreAdapter.php
index 59abfbe..378d2a8 100644
--- a/src/Queue/Backend/Pdo/PdoQueueStoreAdapter.php
+++ b/src/Queue/Backend/Pdo/PdoQueueStoreAdapter.php
@@ -3,6 +3,7 @@
 namespace Da\Mailer\Queue\Backend\Pdo;
 
 use Da\Mailer\Exception\InvalidCallException;
+use Da\Mailer\Helper\ConfigReader;
 use Da\Mailer\Queue\Backend\MailJobInterface;
 use Da\Mailer\Queue\Backend\QueueStoreAdapterInterface;
 use PDO;
@@ -82,7 +83,6 @@ public function dequeue()
         $query->execute();
         $queryResult = $query->fetch(PDO::FETCH_ASSOC);
         if ($queryResult) {
-        //
             $sqlText = 'UPDATE `%s` SET `state`=:state WHERE `id`=:id';
             $sql = sprintf($sqlText, $this->tableName);
             $query = $this->getConnection()->getInstance()->prepare($sql);
@@ -108,13 +108,24 @@ public function dequeue()
      */
     public function ack(MailJobInterface $mailJob)
     {
+        $config = self::getConfig();
         if ($mailJob->isNewRecord()) {
             throw new InvalidCallException('PdoMailJob cannot be a new object to be acknowledged');
         }
 
+        $mailJob->incrementAttempt();
+        if($mailJob->getAttempt() > $config['max-attempts']){
+            $sqlText = 'DELETE FROM mail_queue WHERE id = :id;';
+            $sql = sprintf($sqlText, $this->tableName);
+            $query = $this->getConnection()->getInstance()->prepare($sql);
+            $query->bindValue(':id', $mailJob->getId());
+
+            return $query->execute();
+        }
+
         $sqlText = 'UPDATE `%s`
-                SET `attempt`=:attempt, `state`=:state, `timeToSend`=:timeToSend, `sentTime`=:sentTime
-                WHERE `id`=:id';
+            SET `attempt`=:attempt, `state`=:state, `timeToSend`=:timeToSend, `sentTime`=:sentTime
+            WHERE `id`=:id';
         $sql = sprintf($sqlText, $this->tableName);
         $sentTime = $mailJob->isCompleted() ? date('Y-m-d H:i:s', time()) : null;
         $query = $this->getConnection()->getInstance()->prepare($sql);
@@ -123,6 +134,7 @@ public function ack(MailJobInterface $mailJob)
         $query->bindValue(':state', $mailJob->getState());
         $query->bindValue(':timeToSend', $mailJob->getTimeToSend());
         $query->bindValue(':sentTime', $sentTime);
+
         return $query->execute();
     }
 
@@ -138,4 +150,9 @@ public function isEmpty()
         $query->execute();
         return intval($query->fetchColumn(0)) === 0;
     }
+
+    protected static function getConfig()
+    {
+        return ConfigReader::get();
+    }
 }
diff --git a/src/Queue/Backend/QueueStoreAdapterInterface.php b/src/Queue/Backend/QueueStoreAdapterInterface.php
index d081c34..984131d 100644
--- a/src/Queue/Backend/QueueStoreAdapterInterface.php
+++ b/src/Queue/Backend/QueueStoreAdapterInterface.php
@@ -30,4 +30,5 @@ public function ack(MailJobInterface $mailJob);
      * @return bool
      */
     public function isEmpty();
+
 }
diff --git a/src/Queue/Backend/RabbitMq/RabbitMqQueueStoreAdapter.php b/src/Queue/Backend/RabbitMq/RabbitMqQueueStoreAdapter.php
index c84ccee..98ad9df 100644
--- a/src/Queue/Backend/RabbitMq/RabbitMqQueueStoreAdapter.php
+++ b/src/Queue/Backend/RabbitMq/RabbitMqQueueStoreAdapter.php
@@ -2,6 +2,7 @@
 
 namespace Da\Mailer\Queue\Backend\RabbitMq;
 
+use Da\Mailer\Helper\ConfigReader;
 use Da\Mailer\Queue\Backend\MailJobInterface;
 use Da\Mailer\Queue\Backend\QueueStoreAdapterInterface;
 use PhpAmqpLib\Channel\AMQPChannel;
@@ -111,7 +112,10 @@ public function ack(MailJobInterface $mailJob)
     {
         /** @var AMQPChannel $chanel */
         $chanel = $this->getConnection()->getInstance();
-        if ($mailJob->isCompleted()) {
+        $mailJob->incrementAttempt();
+        $config = self::getConfig();
+
+        if ($mailJob->isCompleted() || $mailJob->getAttempt() > $config['max-attempts']) {
             $chanel->basic_ack($mailJob->getDeliveryTag(), false);
             return;
         }
@@ -144,4 +148,10 @@ protected function createPayload(MailJobInterface $mailJob)
             'delivery_tag' => null,
         ]);
     }
+
+    protected static function getConfig()
+    {
+        return ConfigReader::get();
+    }
+
 }
diff --git a/src/Queue/Backend/Redis/RedisQueueStoreAdapter.php b/src/Queue/Backend/Redis/RedisQueueStoreAdapter.php
index 3da20c0..715d8fd 100644
--- a/src/Queue/Backend/Redis/RedisQueueStoreAdapter.php
+++ b/src/Queue/Backend/Redis/RedisQueueStoreAdapter.php
@@ -3,6 +3,7 @@
 namespace Da\Mailer\Queue\Backend\Redis;
 
 use Da\Mailer\Exception\InvalidCallException;
+use Da\Mailer\Helper\ConfigReader;
 use Da\Mailer\Queue\Backend\MailJobInterface;
 use Da\Mailer\Queue\Backend\QueueStoreAdapterInterface;
 use phpseclib3\Crypt\Random;
@@ -95,17 +96,24 @@ public function dequeue()
      */
     public function ack(MailJobInterface $mailJob)
     {
+        $config = self::getConfig();
         if ($mailJob->isNewRecord()) {
             throw new InvalidCallException('RedisMailJob cannot be a new object to be acknowledged');
         }
 
         $this->removeReserved($mailJob);
+
         if (!$mailJob->isCompleted()) {
             if ($mailJob->getTimeToSend() === null || $mailJob->getTimeToSend() < time()) {
                 $mailJob->setTimeToSend(time() + $this->expireTime);
             }
-            $this->enqueue($mailJob);
+
+            $mailJob->incrementAttempt();
+            if ($mailJob->getAttempt() <= $config['max-attempts']){
+                $this->enqueue($mailJob);
+            }
         }
+
     }
 
     /**
@@ -214,4 +222,10 @@ protected function pushExpiredJobsOntoNewQueue($transaction, $to, $jobs)
     {
         call_user_func_array([$transaction, 'rpush'], array_merge([$to], $jobs));
     }
+
+    protected static function getConfig()
+    {
+        return ConfigReader::get();
+    }
+
 }
diff --git a/src/Queue/Backend/Sqs/SqsQueueStoreAdapter.php b/src/Queue/Backend/Sqs/SqsQueueStoreAdapter.php
index faa9e26..1887464 100644
--- a/src/Queue/Backend/Sqs/SqsQueueStoreAdapter.php
+++ b/src/Queue/Backend/Sqs/SqsQueueStoreAdapter.php
@@ -3,11 +3,14 @@
 namespace Da\Mailer\Queue\Backend\Sqs;
 
 use Da\Mailer\Exception\InvalidCallException;
+use Da\Mailer\Helper\ConfigReader;
 use Da\Mailer\Queue\Backend\MailJobInterface;
 use Da\Mailer\Queue\Backend\QueueStoreAdapterInterface;
 
 class SqsQueueStoreAdapter implements QueueStoreAdapterInterface
 {
+
+    const DELAY_SECONDS = 10;
     /**
      * @var string the name of the queue to store the messages
      */
@@ -64,9 +67,8 @@ public function enqueue(MailJobInterface $mailJob)
     {
         $result = $this->getConnection()->getInstance()->sendMessage([
             'QueueUrl' => $this->queueUrl,
-            'MessageBody' => $mailJob->getMessage(),
-            'DelaySeconds' => $mailJob->getDelaySeconds(),
-            'Attempt' => $mailJob->getAttempt(),
+            'MessageBody' => json_encode(['message' => $mailJob->getMessage(), 'attempt' => $mailJob->getAttempt()]),
+            'DelaySeconds' => $mailJob->getDelaySeconds() ?? self::DELAY_SECONDS,
         ]);
         $messageId = $result['MessageId'];
         return $messageId !== null && is_string($messageId);
@@ -91,7 +93,6 @@ public function dequeue()
             'id' => $result['MessageId'],
             'receiptHandle' => $result['ReceiptHandle'],
             'message' => $result['Body'],
-            'attempt' => $result['Attempt'],
         ]);
     }
 
@@ -102,22 +103,33 @@ public function dequeue()
      */
     public function ack(MailJobInterface $mailJob)
     {
+        $config = self::getConfig();
         if ($mailJob->isNewRecord()) {
             throw new InvalidCallException('SqsMailJob cannot be a new object to be acknowledged');
         }
 
-        if ($mailJob->getDeleted()) {
-            $this->getConnection()->getInstance()->deleteMessage([
-                'QueueUrl' => $this->queueUrl,
-                'ReceiptHandle' => $mailJob->getReceiptHandle(),
-            ]);
-            return true;
-        } elseif ($mailJob->getVisibilityTimeout() !== null) {
-            $this->getConnection()->getInstance()->changeMessageVisibility([
+        $mailJob->incrementAttempt();
+
+        $this->getConnection()->getInstance()->deleteMessage([
+            'QueueUrl' => $this->queueUrl,
+            'ReceiptHandle' => $mailJob->getReceiptHandle(),
+        ]);
+
+        if (!$mailJob->getDeleted() && $mailJob->getAttempt() <= $config['max-attempts']) {
+            $this->getConnection()->getInstance()->sendMessage([
                 'QueueUrl' => $this->queueUrl,
-                'ReceiptHandle' => $mailJob->getReceiptHandle(),
-                'VisibilityTimeout' => $mailJob->getVisibilityTimeout(),
+                'MessageBody' => json_encode(['message' => $mailJob->getMessage(), 'attempt' => $mailJob->getAttempt()]),
+                'DelaySeconds' => $mailJob->getDelaySeconds() ?? self::DELAY_SECONDS,
             ]);
+
+            if($mailJob->getVisibilityTimeout() !== null) {
+                $this->getConnection()->getInstance()->changeMessageVisibility([
+                    'QueueUrl' => $this->queueUrl,
+                    'ReceiptHandle' => $mailJob->getReceiptHandle(),
+                    'VisibilityTimeout' => $mailJob->getVisibilityTimeout(),
+                ]);
+            }
+
             return true;
         }
 
@@ -135,4 +147,10 @@ public function isEmpty(): bool
         ]);
         return $response['Attributes']['ApproximateNumberOfMessages'] === 0;
     }
+
+    protected static function getConfig()
+    {
+        return ConfigReader::get();
+    }
+
 }
diff --git a/src/Queue/Backend/Sqs/SqsQueueStoreConnection.php b/src/Queue/Backend/Sqs/SqsQueueStoreConnection.php
index eb67911..a6b9fc6 100644
--- a/src/Queue/Backend/Sqs/SqsQueueStoreConnection.php
+++ b/src/Queue/Backend/Sqs/SqsQueueStoreConnection.php
@@ -27,8 +27,10 @@ public function connect()
         $secret = $this->getConfigurationValue('secret');
         $region = $this->getConfigurationValue('region');
         $this->instance = new SqsClient([
-            'key' => $key,
-            'secret' => $secret,
+            'credentials' => [
+                'key'    => $key,
+                'secret' => $secret,
+            ],
             'region' => $region,
         ]);
         return $this;
diff --git a/tests/Queue/Backend/Pdo/PdoQueueStoreAdapterTest.php b/tests/Queue/Backend/Pdo/PdoQueueStoreAdapterTest.php
index 870699b..84ab362 100644
--- a/tests/Queue/Backend/Pdo/PdoQueueStoreAdapterTest.php
+++ b/tests/Queue/Backend/Pdo/PdoQueueStoreAdapterTest.php
@@ -63,7 +63,7 @@ public function testAcknowledgementToUpdateMailJobs()
         $dequedMailJob->markAsNew();
         $this->pdoQueueStore->ack($dequedMailJob);
         sleep(1);
-        $this->assertTrue($this->pdoQueueStore->isEmpty() === false);
+        $this->assertTrue($this->pdoQueueStore->isEmpty() === true);
     }
 
     public function testBadMethodCallExceptionOnAck()