Jakarta Mail API

import javax.mail.*;
import javax.mail.internet.*;
import javax.mail.search.*;
import javax.mail.event.*;
import java.util.Properties;
import javax.activation.DataHandler;

// Create session
Properties props = new Properties();
props.put("mail.smtp.host", "smtp.example.com");
props.put("mail.smtp.port", "587");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.starttls.enable", "true");

Session session = Session.getInstance(props, new Authenticator() {
    protected PasswordAuthentication getPasswordAuthentication() {
        return new PasswordAuthentication("username", "password");
    }
});

// Create and send message
Message message = new MimeMessage(session);
message.setFrom(new InternetAddress("sender@example.com"));
message.setRecipients(Message.RecipientType.TO, 
                      InternetAddress.parse("recipient@example.com"));
message.setSubject("Hello World");
message.setText("This is a test message.");

Transport.send(message);

// Read messages
Store store = session.getStore("imap");
store.connect("imap.example.com", "username", "password");
Folder inbox = store.getFolder("INBOX");
inbox.open(Folder.READ_ONLY);
Message[] messages = inbox.getMessages();

class Session {
    // Static factory methods
    public static Session getInstance(Properties props);
    public static Session getInstance(Properties props, Authenticator authenticator);
    public static synchronized Session getDefaultInstance(Properties props);
    public static synchronized Session getDefaultInstance(Properties props, Authenticator authenticator);
    
    // Store and Transport access
    public Store getStore() throws NoSuchProviderException;
    public Store getStore(String protocol) throws NoSuchProviderException;
    public Store getStore(URLName url) throws NoSuchProviderException;
    public Store getStore(Provider provider) throws NoSuchProviderException;
    public Transport getTransport() throws NoSuchProviderException;
    public Transport getTransport(String protocol) throws NoSuchProviderException;
    public Transport getTransport(URLName url) throws NoSuchProviderException;
    public Transport getTransport(Provider provider) throws NoSuchProviderException;
    public Transport getTransport(Address address) throws NoSuchProviderException;
    
    // Folder access
    public Folder getFolder(URLName url) throws MessagingException;
    
    // Properties and configuration
    public Properties getProperties();
    public String getProperty(String name);
    
    // Provider management
    public synchronized Provider[] getProviders();
    public synchronized Provider getProvider(String protocol) throws NoSuchProviderException;
    public synchronized void setProvider(Provider provider) throws NoSuchProviderException;
    public synchronized void addProvider(Provider provider);
    
    // Authentication
    public void setPasswordAuthentication(URLName url, PasswordAuthentication pw);
    public PasswordAuthentication getPasswordAuthentication(URLName url);
    public PasswordAuthentication requestPasswordAuthentication(InetAddress addr, int port, String protocol, String prompt, String defaultUserName);
    
    // Debug support
    public synchronized void setDebug(boolean debug);
    public synchronized boolean getDebug();
    public synchronized void setDebugOut(PrintStream out);
    public synchronized PrintStream getDebugOut();
    
    // Protocol configuration
    public synchronized void setProtocolForAddress(String addresstype, String protocol);
}

abstract class Message implements Part {
    // Address management
    public abstract Address[] getFrom() throws MessagingException;
    public abstract void setFrom() throws MessagingException;
    public abstract void setFrom(Address address) throws MessagingException;
    public abstract void addFrom(Address[] addresses) throws MessagingException;
    public abstract Address[] getRecipients(RecipientType type) throws MessagingException;
    public abstract void setRecipients(RecipientType type, Address[] addresses) throws MessagingException;
    public abstract void addRecipients(RecipientType type, Address[] addresses) throws MessagingException;
    
    // Subject and dates
    public abstract String getSubject() throws MessagingException;
    public abstract void setSubject(String subject) throws MessagingException;
    public abstract Date getSentDate() throws MessagingException;
    public abstract void setSentDate(Date date) throws MessagingException;
    public abstract Date getReceivedDate() throws MessagingException;
    
    // Flag management
    public abstract Flags getFlags() throws MessagingException;
    public abstract void setFlags(Flags flag, boolean set) throws MessagingException;
    
    // Operations
    public abstract Message reply(boolean replyToAll) throws MessagingException;
    public abstract void saveChanges() throws MessagingException;
}

abstract class Transport extends Service {
    // Static send methods
    public static void send(Message msg) throws MessagingException;
    public static void send(Message msg, Address[] addresses) throws MessagingException;
    public static void send(Message msg, String user, String password) throws MessagingException;
    public static void send(Message msg, Address[] addresses, String user, String password) throws MessagingException;
    
    // Instance methods
    public abstract void sendMessage(Message msg, Address[] addresses) throws MessagingException;
}

class MimeMessage extends Message implements MimePart {
    public MimeMessage(Session session);
    public MimeMessage(Session session, InputStream is) throws MessagingException;
    public MimeMessage(MimeMessage source) throws MessagingException;
    
    public void setText(String text) throws MessagingException;
    public void setContent(Object o, String type) throws MessagingException;
    public void setContent(Multipart mp) throws MessagingException;
    public Object getContent() throws IOException, MessagingException;
    public String getContentType() throws MessagingException;
    
    public void setHeader(String name, String value) throws MessagingException;
    public String[] getHeader(String name) throws MessagingException;
    public void addHeader(String name, String value) throws MessagingException;
    public void removeHeader(String name) throws MessagingException;
    
    public String getMessageID() throws MessagingException;
    public void updateHeaders() throws MessagingException;
}

class InternetAddress extends Address {
    public InternetAddress();
    public InternetAddress(String address) throws AddressException;
    public InternetAddress(String address, String personal) throws AddressException;
    public InternetAddress(String address, String personal, String charset) throws UnsupportedEncodingException;
    
    public String getAddress();
    public void setAddress(String address);
    public String getPersonal();
    public void setPersonal(String name) throws UnsupportedEncodingException;
    
    public static InternetAddress[] parse(String addresslist) throws AddressException;
    public static InternetAddress[] parse(String addresslist, boolean strict) throws AddressException;
    public static InternetAddress[] parseHeader(String addresslist, boolean strict) throws AddressException;
    
    public void validate() throws AddressException;
    public boolean isGroup();
    public InternetAddress[] getGroup(boolean strict) throws AddressException;
}

class MimeMultipart extends Multipart {
    public MimeMultipart();
    public MimeMultipart(String subtype) throws MessagingException;
    public MimeMultipart(DataSource ds) throws MessagingException;
    
    public void addBodyPart(BodyPart part) throws MessagingException;
    public void addBodyPart(BodyPart part, int index) throws MessagingException;
    public BodyPart getBodyPart(int index) throws MessagingException;
    public boolean removeBodyPart(BodyPart part) throws MessagingException;
    public int getCount() throws MessagingException;
    
    public String getPreamble() throws MessagingException;
    public void setPreamble(String preamble) throws MessagingException;
}

abstract class Folder implements AutoCloseable {
    abstract void open(int mode) throws MessagingException;
    abstract Message[] getMessages() throws MessagingException;
    abstract void appendMessages(Message[] msgs) throws MessagingException;
    abstract Message[] expunge() throws MessagingException;
    abstract Folder[] list(String pattern) throws MessagingException;
}

abstract class Store extends Service {
    abstract Folder getDefaultFolder() throws MessagingException;
    abstract Folder getFolder(String name) throws MessagingException;
}

abstract class SearchTerm implements Serializable {
    abstract boolean match(Message msg);
}

class AndTerm extends SearchTerm {
    AndTerm(SearchTerm t1, SearchTerm t2);
    AndTerm(SearchTerm[] terms);
}

class SubjectTerm extends StringTerm {
    SubjectTerm(String pattern);
}

class FromTerm extends AddressTerm {
    FromTerm(Address address);
}

interface MessageCountListener extends EventListener {
    void messagesAdded(MessageCountEvent e);
    void messagesRemoved(MessageCountEvent e);
}

interface ConnectionListener extends EventListener {
    void opened(ConnectionEvent e);
    void closed(ConnectionEvent e);
    void disconnected(ConnectionEvent e);
}

abstract class MessageCountAdapter implements MessageCountListener {
    // Empty implementations for optional override
}

class Properties extends Hashtable<Object,Object> {
    String getProperty(String key);
    Object setProperty(String key, String value);
}

abstract class Authenticator {
    protected PasswordAuthentication getPasswordAuthentication();
}

class PasswordAuthentication {
    PasswordAuthentication(String userName, String password);
    String getUserName();
    String getPassword();
}

class MessagingException extends Exception {
    MessagingException();
    MessagingException(String s);
    MessagingException(String s, Exception e);
}

class Flags implements Cloneable, Serializable {
    Flags();
    Flags(Flag flag);
    void add(Flag flag);
    boolean contains(Flag flag);
    
    static class Flag {
        static final Flag ANSWERED;
        static final Flag DELETED;
        static final Flag DRAFT;
        static final Flag FLAGGED;
        static final Flag RECENT;
        static final Flag SEEN;
    }
}