Is it possible to send an email from my Java application using a GMail account? I have configured my company mail server with Java app to send email, but that's not going to cut it when I distribute the application. Answers with any of using Hotmail, Yahoo or GMail are acceptable.
14 Answers
First download the JavaMail API and make sure the relevant jar files are in your classpath.
Here's a full working example using GMail.
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;
public class Main {
private static String USER_NAME = "*****"; // GMail user name (just the part before "@gmail.com")
private static String PASSWORD = "********"; // GMail password
private static String RECIPIENT = "lizard.bill@myschool.edu";
public static void main(String[] args) {
String from = USER_NAME;
String pass = PASSWORD;
String[] to = { RECIPIENT }; // list of recipient email addresses
String subject = "Java send mail example";
String body = "Welcome to JavaMail!";
sendFromGMail(from, pass, to, subject, body);
}
private static void sendFromGMail(String from, String pass, String[] to, String subject, String body) {
Properties props = System.getProperties();
String host = "smtp.gmail.com";
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.host", host);
props.put("mail.smtp.user", from);
props.put("mail.smtp.password", pass);
props.put("mail.smtp.port", "587");
props.put("mail.smtp.auth", "true");
Session session = Session.getDefaultInstance(props);
MimeMessage message = new MimeMessage(session);
try {
message.setFrom(new InternetAddress(from));
InternetAddress[] toAddress = new InternetAddress[to.length];
// To get the array of addresses
for( int i = 0; i < to.length; i++ ) {
toAddress[i] = new InternetAddress(to[i]);
}
for( int i = 0; i < toAddress.length; i++) {
message.addRecipient(Message.RecipientType.TO, toAddress[i]);
}
message.setSubject(subject);
message.setText(body);
Transport transport = session.getTransport("smtp");
transport.connect(host, from, pass);
transport.sendMessage(message, message.getAllRecipients());
transport.close();
}
catch (AddressException ae) {
ae.printStackTrace();
}
catch (MessagingException me) {
me.printStackTrace();
}
}
}
Naturally, you'll want to do more in the catch blocks than print the stack trace as I did in the example code above. (Remove the catch blocks to see which method calls from the JavaMail API throw exceptions so you can better see how to properly handle them.)
Thanks to @jodonnel and everyone else who answered. I'm giving him a bounty because his answer led me about 95% of the way to a complete answer.
Something like this (sounds like you just need to change your SMTP server):
String host = "smtp.gmail.com";
String from = "user name";
Properties props = System.getProperties();
props.put("mail.smtp.host", host);
props.put("mail.smtp.user", from);
props.put("mail.smtp.password", "asdfgh");
props.put("mail.smtp.port", "587"); // 587 is the port number of yahoo mail
props.put("mail.smtp.auth", "true");
Session session = Session.getDefaultInstance(props, null);
MimeMessage message = new MimeMessage(session);
message.setFrom(new InternetAddress(from));
InternetAddress[] to_address = new InternetAddress[to.length];
int i = 0;
// To get the array of addresses
while (to[i] != null) {
to_address[i] = new InternetAddress(to[i]);
i++;
}
System.out.println(Message.RecipientType.TO);
i = 0;
while (to_address[i] != null) {
message.addRecipient(Message.RecipientType.TO, to_address[i]);
i++;
}
message.setSubject("sending in a group");
message.setText("Welcome to JavaMail");
// alternately, to send HTML mail:
// message.setContent("<p>Welcome to JavaMail</p>", "text/html");
Transport transport = session.getTransport("smtp");
transport.connect("smtp.mail.yahoo.co.in", "user name", "asdfgh");
transport.sendMessage(message, message.getAllRecipients());
transport.close();
Other people have good answers above, but I wanted to add a note on my experience here. I've found that when using Gmail as an outbound SMTP server for my webapp, Gmail only lets me send ~10 or so messages before responding with an anti-spam response that I have to manually step through to re-enable SMTP access. The emails I was sending were not spam, but were website "welcome" emails when users registered with my system. So, YMMV, and I wouldn't rely on Gmail for a production webapp. If you're sending email on a user's behalf, like an installed desktop app (where the user enters their own Gmail credentials), you may be okay.
Also, if you're using Spring, here's a working config to use Gmail for outbound SMTP:
<bean id="mailSender" class="org.springframework.mail.javamail.JavaMailSenderImpl">
<property name="defaultEncoding" value="UTF-8"/>
<property name="host" value="smtp.gmail.com"/>
<property name="port" value="465"/>
<property name="username" value="${mail.username}"/>
<property name="password" value="${mail.password}"/>
<property name="javaMailProperties">
<value>
mail.debug=true
mail.smtp.auth=true
mail.smtp.socketFactory.class=java.net.SocketFactory
mail.smtp.socketFactory.fallback=false
</value>
</property>
</bean>
Even though this question is closed, I'd like to post a counter solution, but now using Simple Java Mail (Open Source JavaMail smtp wrapper):
final Email email = new Email();
String host = "smtp.gmail.com";
Integer port = 587;
String from = "username";
String pass = "password";
String[] to = {"to@gmail.com"};
email.setFromAddress("", from);
email.setSubject("sending in a group");
for( int i=0; i < to.length; i++ ) {
email.addRecipient("", to[i], RecipientType.TO);
}
email.setText("Welcome to JavaMail");
new Mailer(host, port, from, pass).sendMail(email);
// you could also still use your mail session instead
new Mailer(session).sendMail(email);
Value added:
- encoding pitfalls in subject, message and display name
- only one magic property is needed for modern java mail library versions
Session.getInstance()recommended overSession.getDefaultInstance()- attachment in the same example
- still works after Google turns off less secure apps: Enable 2-factor authentication in your organization -> turn on 2FA -> generate app password.
import java.io.File;
import java.nio.charset.StandardCharsets;
import java.util.Properties;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.activation.DataHandler;
import javax.mail.Message;
import javax.mail.Session;
import javax.mail.Transport;
import javax.mail.internet.InternetAddress;
import javax.mail.internet.MimeBodyPart;
import javax.mail.internet.MimeMessage;
import javax.mail.internet.MimeMultipart;
import javax.mail.util.ByteArrayDataSource;
public class Gmailer {
private static final Logger LOGGER = Logger.getLogger(Gmailer.class.getName());
public static void main(String[] args) {
send();
}
public static void send() {
Transport transport = null;
try {
String accountEmail = "account@source.com";
String accountAppPassword = "";
String displayName = "Display-Name 東";
String replyTo = "reply-to@source.com";
String to = "to@target.com";
String cc = "cc@target.com";
String bcc = "bcc@target.com";
String subject = "Subject 東";
String message = "<span style='color: red;'>東</span>";
String type = "html"; // or "plain"
String mimeTypeWithEncoding = "text/" + type + "; charset=" + StandardCharsets.UTF_8.name();
File attachmentFile = new File("Attachment.pdf");
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types
String attachmentMimeType = "application/pdf";
byte[] bytes = ...; // read file to byte array
Properties properties = System.getProperties();
properties.put("mail.debug", "true");
// i found that this is the only property necessary for a modern java mail version
properties.put("mail.smtp.starttls.enable", "true");
// https://javaee.github.io/javamail/FAQ#getdefaultinstance
Session session = Session.getInstance(properties);
MimeMessage mimeMessage = new MimeMessage(session);
// probably best to use the account email address, to avoid landing in spam or blacklists
// not even sure if the server would accept a differing from address
InternetAddress from = new InternetAddress(accountEmail);
from.setPersonal(displayName, StandardCharsets.UTF_8.name());
mimeMessage.setFrom(from);
mimeMessage.setReplyTo(InternetAddress.parse(replyTo));
mimeMessage.setRecipients(Message.RecipientType.TO, InternetAddress.parse(to));
mimeMessage.setRecipients(Message.RecipientType.CC, InternetAddress.parse(cc));
mimeMessage.setRecipients(Message.RecipientType.BCC, InternetAddress.parse(bcc));
mimeMessage.setSubject(subject, StandardCharsets.UTF_8.name());
MimeMultipart multipart = new MimeMultipart();
MimeBodyPart messagePart = new MimeBodyPart();
messagePart.setContent(mimeMessage, mimeTypeWithEncoding);
multipart.addBodyPart(messagePart);
MimeBodyPart attachmentPart = new MimeBodyPart();
attachmentPart.setDataHandler(new DataHandler(new ByteArrayDataSource(bytes, attachmentMimeType)));
attachmentPart.setFileName(attachmentFile.getName());
multipart.addBodyPart(attachmentPart);
mimeMessage.setContent(multipart);
transport = session.getTransport();
transport.connect("smtp.gmail.com", 587, accountEmail, accountAppPassword);
transport.sendMessage(mimeMessage, mimeMessage.getAllRecipients());
}
catch(Exception e) {
// I prefer to bubble up exceptions, so the caller has the info that someting went wrong, and gets a chance to handle it.
// I also prefer not to force the exception in the signature.
throw e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);
}
finally {
if(transport != null) {
try {
transport.close();
}
catch(Exception e) {
LOGGER.log(Level.WARNING, "failed to close java mail transport: " + e);
}
}
}
}
}
This is what I do when i want to send email with attachment, work fine. :)
public class NewClass {
public static void main(String[] args) {
try {
Properties props = System.getProperties();
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.host", "smtp.gmail.com");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.port", "465"); // smtp port
Authenticator auth = new Authenticator() {
@Override
protected PasswordAuthentication getPasswordAuthentication() {
return new PasswordAuthentication("username-gmail", "password-gmail");
}
};
Session session = Session.getDefaultInstance(props, auth);
MimeMessage msg = new MimeMessage(session);
msg.setFrom(new InternetAddress("username-gmail@gmail.com"));
msg.setSubject("Try attachment gmail");
msg.setRecipient(RecipientType.TO, new InternetAddress("username-gmail@gmail.com"));
//add atleast simple body
MimeBodyPart body = new MimeBodyPart();
body.setText("Try attachment");
//do attachment
MimeBodyPart attachMent = new MimeBodyPart();
FileDataSource dataSource = new FileDataSource(new File("file-sent.txt"));
attachMent.setDataHandler(new DataHandler(dataSource));
attachMent.setFileName("file-sent.txt");
attachMent.setDisposition(MimeBodyPart.ATTACHMENT);
Multipart multipart = new MimeMultipart();
multipart.addBodyPart(body);
multipart.addBodyPart(attachMent);
msg.setContent(multipart);
Transport.send(msg);
} catch (AddressException ex) {
Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);
} catch (MessagingException ex) {
Logger.getLogger(NewClass.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
An easy route would be to have the gmail account configured/enabled for POP3 access. This would allow you to send out via normal SMTP through the gmail servers.
Then you'd just send through smtp.gmail.com (on port 587)
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