title: Static Configuration for Switfmailer using yii2 won't send mails
body: <p>using following static cofiguration will cause exception like this.</p>
  
  <pre><code>Swift_TransportException: Failed to authenticate on SMTP server with username "thomas.kipp@eisvogel-online-software.de" using 3 possible authenticators in
  </code></pre>
  
  <p>Using mail client will send mail without any problems,so following parameter basically are correct</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>'mailer' =&gt; [
              'class' =&gt; 'yii\swiftmailer\Mailer',
              'viewPath' =&gt; '@common/mail',
              'useFileTransport' =&gt; false, //set this property to true to send mails to mail emulator. Set this property to false to send real mails.              
              'transport' =&gt; [
                  'class' =&gt; 'Swift_SmtpTransport',
                  'host' =&gt; 'smtp.strato.de',
                  'username' =&gt; 'thomas.kipp@eisvogel-online-software.de',
                  'password' =&gt; 'top secret',
                  'port' =&gt; '587',
                  'encryption' =&gt; 'tls',
              ],
          ],</code></pre>
  </div>
  </div>
  </p>
  
  <p>What is wrong with this configuration? Following configuration:</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-html lang-html prettyprint-override"><code>     'mailer' =&gt; [
              'class' =&gt; 'yii\swiftmailer\Mailer',
              'viewPath' =&gt; '@common/mail',
              'useFileTransport' =&gt; false, //set this property to true to send mails to mail emulator. Set this property to false to send real mails.              
              'transport' =&gt; [
                  'class' =&gt; 'Swift_SmtpTransport',
                  'host' =&gt; 'smtp.gmail.com',
                  'username' =&gt; 'tklustig.thomas@gmail.com',
                  'password' =&gt; 'top secret',
                  'port' =&gt; '587',
                  'encryption' =&gt; 'tls',
              ],
          ],</code></pre>
  </div>
  </div>
  </p>
  
  <p>will throw out error like this:</p>
  
  <pre><code>Swift_TransportException: Connection could not be established with host smtp.gmail.com [Connection timed out #145] in
  </code></pre>
  
  <p>Same thing with gmx. I am not able any more, sending mails using Swiftmailer. What could I do?</p>