title: java.lang.NoClassDefFoundError: javax/activation/DataContentHandler
body: <p>I'am developing a webapp using google app engine and maven in intelliJ IDEA.</p>
  
  <p>So far so good until I tried to send an email using <code>javax.mail</code> and I get this error: </p>
  
  <pre><code>java.lang.NoClassDefFoundError: javax/activation/DataContentHandler
  </code></pre>
  
  <p>I have already put the dependencies needed (<code>javax.activation</code> &amp; <code>javax.mail</code>) in the <code>pom.xml</code> and still this error occurs.</p>
  
  <p>One way to fix it locally is to add "--add-modules java.activation" in vm options and when i run it locally its working fine and sending the email, but when I'am deploying the app its not working.</p>
  
  <p>And my question is, 
  is there any way to pass the vm argument to maven or anywhere else so it will run without the error when I'll deploy the app. </p>
  
  <p>Or is there any other way to do this (with <code>javax.mail</code> or not) ?</p>
  
  <p>My java version is: <code>openjdk 10.0.2</code></p>