diff --git a/lib/kolab_sync_logger.php b/lib/kolab_sync_logger.php
--- a/lib/kolab_sync_logger.php
+++ b/lib/kolab_sync_logger.php
@@ -30,6 +30,7 @@
 {
     public $mode;
 
+    protected $log_driver;
     protected $logfile;
     protected $format;
     protected $log_dir;
@@ -44,6 +45,7 @@
 
         $this->mode    = intval($mode);
         $this->logfile = $rcube->config->get('activesync_log_file');
+        $this->log_driver = $rcube->config->get('log_driver');
         $this->format  = $rcube->config->get('log_date_format', 'd-M-Y H:i:s O');
         $this->log_dir = $rcube->config->get('log_dir');
 
@@ -149,6 +151,13 @@
         $date    = rcube_utils::date_format($this->format);
         $logline = sprintf("[%s]: [%s] %s\n", $date, $method, $message);
 
+        // write message with file name when configured to log to STDOUT
+        if ($this->log_driver == 'stdout') {
+            $stdout = "php://stdout";
+            file_put_contents($stdout, $logline, FILE_APPEND);
+            return;
+        }
+
         if ($fp = @fopen($logfile, 'a')) {
             fwrite($fp, $logline);
             fflush($fp);