System.Net.Mail.SmtpTransport.ReleaseConnection C# (CSharp) Method

        internal void ReleaseConnection()
        {
            if (_connection != null)
            {
                _connection.ReleaseConnection();
            }
        }

 protected virtual void Dispose(bool disposing)
 {
     if (disposing && !_disposed)
     {
         if (InCall && !_cancelled)
         {
             _cancelled = true;
             Abort();
         }
         else
         {
             _transport?.ReleaseConnection();
         }
         _timer?.Dispose();
         _disposed = true;
     }
 }