Caused by java.lang.noclassdeffounderror javax mail session tomcat5

A classic error!

The NoClassDefFoundError exception in Java is thrown when the Java Virtual Machine (JVM) or the Java compiler (javac) cannot find or load a particular class (or interface) at runtime.

In your case, the error is specifically related to the javax.mail package, which is part of the JavaMail API. This API is used to send and receive email messages in Java applications.

Here are a few possible reasons why you're seeing this error:

  1. Missing javax.mail library: Make sure that you have the javax.mail library (also known as JavaMail API) in your Tomcat's classpath. You can download the library from the official Oracle website or use a Maven dependency (if you're using Maven).
  2. Incorrect library version: Ensure that the version of the javax.mail library you're using is compatible with your Tomcat version. For example, if you're using Tomcat 5, you may need to use an older version of JavaMail API (e.g., 1.4.7).
  3. Library not deployed correctly: Verify that the javax.mail library is deployed correctly in your Tomcat instance. Check the Tomcat logs for any errors related to the library deployment.
  4. Conflicting library versions: If you're using multiple libraries that depend on the javax.mail package, ensure that they're using the same version of the library.

To resolve the issue, you can try the following:

  1. Add the javax.mail library to your Tomcat's classpath. You can do this by:
    • Placing the library in the lib directory of your Tomcat installation.
    • Adding the library to your Tomcat's common.loader configuration file (usually conf/server.xml).
  2. Update your pom.xml file (if you're using Maven) to include the correct version of the javax.mail library.
  3. Check the Tomcat logs for any errors related to the library deployment and deployment configuration.
  4. Verify that your application is using the correct version of the javax.mail library.

If you're still experiencing issues, please provide more details about your environment, including your Tomcat version, Java version, and any relevant configuration files.