fix(citrus-mail): jakarta mail implementation

The implemented workaround allows jakarta-mail to find the corresponding classes when opening a new session.
The reported without the workaround error is:

```shell
java.lang.IllegalStateException: Not provider of jakarta.mail.util.StreamProvider was found
    at org.citrusframework.mail.server.MailServerTest.testMultipartMessageSplitting(MailServerTest.java:378)
```

Report in PR: citrusframework/citrus-simulator#163 (comment).

connectors/citrus-docker/pom.xml

@@ -85,10 +85,6 @@
       <artifactId>jakarta.xml.bind-api</artifactId>
     </dependency>
 
-    <dependency>
-      <groupId>jakarta.activation</groupId>
-      <artifactId>jakarta.activation-api</artifactId>
-    </dependency>
     <dependency>
       <groupId>jakarta.annotation</groupId>
       <artifactId>jakarta.annotation-api</artifactId>

endpoints/citrus-mail/pom.xml

@@ -66,27 +66,10 @@
       <artifactId>jackson-databind</artifactId>
     </dependency>
 
-    <dependency>
-      <groupId>jakarta.xml.bind</groupId>
-      <artifactId>jakarta.xml.bind-api</artifactId>
-    </dependency>
-    <dependency>
-      <groupId>org.glassfish.jaxb</groupId>
-      <artifactId>jaxb-runtime</artifactId>
-    </dependency>
-
-    <dependency>
-      <groupId>com.sun.mail</groupId>
-      <artifactId>jakarta.mail</artifactId>
-    </dependency>
     <dependency>
       <groupId>com.icegreen</groupId>
       <artifactId>greenmail</artifactId>
     </dependency>
-    <dependency>
-      <groupId>com.sun.activation</groupId>
-      <artifactId>jakarta.activation</artifactId>
-    </dependency>
 
     <!-- Test scoped dependencies -->
     <dependency>

endpoints/citrus-mail/src/main/java/org/citrusframework/mail/client/MailClient.java

@@ -39,7 +39,7 @@
  * @since 1.4
  */
 public class MailClient extends AbstractEndpoint implements Producer, InitializingPhase {
-    /** Logger */
+
     private static Logger log = LoggerFactory.getLogger(MailClient.class);
 
     /**
@@ -51,7 +51,6 @@ public MailClient() {
 
     /**
      * Default constructor using endpoint configuration.
-     * @param endpointConfiguration
      */
     public MailClient(MailEndpointConfiguration endpointConfiguration) {
         super(endpointConfiguration);
@@ -69,7 +68,8 @@ public void send(Message message, TestContext context) {
         }
 
         MimeMailMessage mimeMessage = getEndpointConfiguration().getMessageConverter().convertOutbound(message, getEndpointConfiguration(), context);
-        getEndpointConfiguration().getJavaMailSender().send(mimeMessage.getMimeMessage());
+
+        withModifiedClassloader(() -> getEndpointConfiguration().getJavaMailSender().send(mimeMessage.getMimeMessage()));
 
         ByteArrayOutputStream bos = new ByteArrayOutputStream();
         Message mailMessage;
@@ -91,6 +91,28 @@ public void send(Message message, TestContext context) {
         log.info(String.format("Mail message was sent to host: '%s://%s:%s'", getEndpointConfiguration().getProtocol(), getEndpointConfiguration().getHost(), getEndpointConfiguration().getPort()));
     }
 
+    /**
+     * The implemented workaround allows jakarta-mail to find the corresponding classes when opening a new session. The
+     * reported without the workaround error is:
+     * <pre>
+     *     java.lang.IllegalStateException: Not provider of jakarta.mail.util.StreamProvider was found
+     * 	           at org.citrusframework.mail.server.MailServerTest.testMultipartMessageSplitting(MailServerTest.java:378)
+     * </pre>
+     * <p>
+     * {@see https://github.com/jakartaee/mail-api/issues/665}
+     */
+    private void withModifiedClassloader(Runnable runnable) {
+        Thread thread = Thread.currentThread();
+        ClassLoader contextClassLoader = thread.getContextClassLoader();
+        thread.setContextClassLoader(getClass().getClassLoader());
+
+        try {
+            runnable.run();
+        } finally {
+            thread.setContextClassLoader(contextClassLoader);
+        }
+    }
+
     /**
      * Creates a message producer for this endpoint for sending messages
      * to this endpoint.
@@ -103,8 +125,6 @@ public Producer createProducer() {
     /**
      * Creates a message consumer for this endpoint. Consumer receives
      * messages on this endpoint.
-     *
-     * @return
      */
     @Override
     public Consumer createConsumer() {

endpoints/citrus-mail/src/main/java/org/citrusframework/mail/server/MailServer.java

@@ -16,13 +16,13 @@
 
 package org.citrusframework.mail.server;
 
-import java.util.List;
-import java.util.Map;
-import java.util.Properties;
-import java.util.Stack;
-import java.util.stream.Collectors;
-import javax.xml.transform.Source;
-
+import com.icegreen.greenmail.mail.MailAddress;
+import com.icegreen.greenmail.user.GreenMailUser;
+import com.icegreen.greenmail.util.GreenMail;
+import com.icegreen.greenmail.util.ServerSetup;
+import jakarta.mail.AuthenticationFailedException;
+import jakarta.mail.Session;
+import jakarta.mail.internet.MimeMessage;
 import org.citrusframework.exceptions.CitrusRuntimeException;
 import org.citrusframework.mail.client.MailEndpointConfiguration;
 import org.citrusframework.mail.message.CitrusMailMessageHeaders;
@@ -36,23 +36,23 @@
 import org.citrusframework.mail.model.MailResponse;
 import org.citrusframework.message.Message;
 import org.citrusframework.server.AbstractServer;
-import com.icegreen.greenmail.mail.MailAddress;
-import com.icegreen.greenmail.user.GreenMailUser;
-import com.icegreen.greenmail.util.GreenMail;
-import com.icegreen.greenmail.util.ServerSetup;
-import jakarta.mail.AuthenticationFailedException;
-import jakarta.mail.Session;
-import jakarta.mail.internet.MimeMessage;
 import org.springframework.mail.javamail.MimeMailMessage;
 
+import javax.xml.transform.Source;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Stack;
+import java.util.stream.Collectors;
+
 /**
  * Mail server implementation starts new SMTP server instance and listens for incoming mail messages. Incoming mail messages
  * are converted to XML representation and forwarded to some message endpoint adapter (e.g. forwarding mail content to
  * a message channel).
- *
- * By default incoming messages are accepted automatically. When auto accept is disabled the endpoint adapter is invoked with
+ * <p>
+ * By default, incoming messages are accepted automatically. When auto accept is disabled the endpoint adapter is invoked with
  * accept request and test case has to decide accept outcome in response.
- *
+ * <p>
  * In case of incoming multipart mail messages the server is able to split the body parts into separate XML messages
  * handled by the endpoint adapter.
  *
@@ -105,6 +105,7 @@ protected void startup() {
             deliver(msg.getMessage());
             return user;
         });
+
         smtpServer.start();
     }
 
@@ -140,8 +141,8 @@ public boolean accept(String from, List<MailAddress> recipients) {
         return acceptResponse.isAccept();
     }
 
-    public void deliver(MimeMessage msg) {
-        MimeMailMessage mimeMailMessage = new MimeMailMessage(msg);
+    public void deliver(MimeMessage mimeMessage) {
+        MimeMailMessage mimeMailMessage = new MimeMailMessage(mimeMessage);
         MailMessage request = messageConverter.convertInbound(mimeMailMessage, getEndpointConfiguration(), null);
         Message response = invokeEndpointAdapter(request);
 
@@ -161,7 +162,6 @@ public void deliver(MimeMessage msg) {
 
     /**
      * Invokes the endpoint adapter with constructed mail message and headers.
-     * @param mail
      */
     protected Message invokeEndpointAdapter(MailMessage mail) {
         if (splitMultipart) {
@@ -174,10 +174,7 @@ protected Message invokeEndpointAdapter(MailMessage mail) {
     /**
      * Split mail message into several messages. Each body and each attachment results in separate message
      * invoked on endpoint adapter. Mail message response if any should be sent only once within test case.
-     * However latest mail response sent by test case is returned, others are ignored.
-     *
-     * @param bodyPart
-     * @param messageHeaders
+     * However, latest mail response sent by test case is returned, others are ignored.
      */
     private Message split(BodyPart bodyPart, Map<String, Object> messageHeaders) {
         MailMessage mailRequest = createMailMessage(messageHeaders, bodyPart.getContent(), bodyPart.getContentType());
@@ -209,10 +206,6 @@ private void fillStack(Message message, Stack<Message> responseStack) {
 
     /**
      * Creates a new mail message model object from message headers.
-     * @param messageHeaders
-     * @param body
-     * @param contentType
-     * @return
      */
     protected MailMessage createMailMessage(Map<String, Object> messageHeaders, String body, String contentType) {
         return MailMessage.request(messageHeaders)
@@ -236,123 +229,126 @@ public MailEndpointConfiguration getEndpointConfiguration() {
     }
 
     /**
-     * Return new mail session if not already created before.
-     * @return
+     * Return a new mail session if not already created before.
+     * <p>
+     * The implemented workaround allows jakarta-mail to find the corresponding classes when opening a new session. The
+     * reported without the workaround error is:
+     * <pre>
+     *     java.lang.IllegalStateException: Not provider of jakarta.mail.util.StreamProvider was found
+     * 	           at org.citrusframework.mail.server.MailServerTest.testMultipartMessageSplitting(MailServerTest.java:378)
+     * </pre>
+     * <p>
+     * {@see https://github.com/jakartaee/mail-api/issues/665}
      */
     public synchronized Session getSession() {
         if (this.mailSession == null) {
-            this.mailSession = Session.getInstance(this.javaMailProperties);
+            Thread thread = Thread.currentThread();
+            ClassLoader contextClassLoader = thread.getContextClassLoader();
+            thread.setContextClassLoader(getClass().getClassLoader());
+
+            try {
+                this.mailSession = Session.getInstance(this.javaMailProperties);
+            } finally {
+                thread.setContextClassLoader(contextClassLoader);
+            }
         }
+
         return this.mailSession;
     }
 
     /**
      * Is auto accept enabled.
-     * @return
      */
     public boolean isAutoAccept() {
         return autoAccept;
     }
 
     /**
      * Enable/disable auto accept feature.
-     * @param autoAccept
      */
     public void setAutoAccept(boolean autoAccept) {
         this.autoAccept = autoAccept;
     }
 
     /**
      * Gets the mail message marshaller.
-     * @return
      */
     public MailMarshaller getMarshaller() {
         return marshaller;
     }
 
     /**
      * Sets the mail message marshaller.
-     * @param marshaller
      */
     public void setMarshaller(MailMarshaller marshaller) {
         this.marshaller = marshaller;
     }
 
     /**
      * Gets the Java mail properties.
-     * @return
      */
     public Properties getJavaMailProperties() {
         return javaMailProperties;
     }
 
     /**
      * Sets the Java mail properties.
-     * @param javaMailProperties
      */
     public void setJavaMailProperties(Properties javaMailProperties) {
         this.javaMailProperties = javaMailProperties;
     }
 
     /**
      * Gets the server port.
-     * @return
      */
     public int getPort() {
         return port;
     }
 
     /**
      * Sets the server port.
-     * @param port
      */
     public void setPort(int port) {
         this.port = port;
     }
 
     /**
      * Gets the smtp server instance.
-     * @return
      */
     public GreenMail getSmtpServer() {
         return smtpServer;
     }
 
     /**
      * Sets the smtp server instance.
-     * @param smtpServer
      */
     public void setSmtpServer(GreenMail smtpServer) {
         this.smtpServer = smtpServer;
     }
 
     /**
      * Gets the split multipart message.
-     * @return
      */
     public boolean isSplitMultipart() {
         return splitMultipart;
     }
 
     /**
      * Sets the split multipart message.
-     * @param splitMultipart
      */
     public void setSplitMultipart(boolean splitMultipart) {
         this.splitMultipart = splitMultipart;
     }
 
     /**
      * Gets the message converter.
-     * @return
      */
     public MailMessageConverter getMessageConverter() {
         return messageConverter;
     }
 
     /**
      * Sets the message converter.
-     * @param messageConverter
      */
     public void setMessageConverter(MailMessageConverter messageConverter) {
         this.messageConverter = messageConverter;