Sending emails with JavaMail

Byron KiourtzoglouNovember 11th, 2012Last Updated: November 11th, 2012

0 87 2 minutes read

Sending a simple text message

// Common variables
String host = "your_smtp_server";
String from = "from_address";
String to = "to_address";
 
// Set properties
Properties props = new Properties();
props.put("mail.smtp.host", host);
props.put("mail.debug", "true");
 
// Get session
Session session = Session.getInstance(props);
 
try {
    // Instantiate a message
    Message msg = new MimeMessage(session);
 
    // Set the FROM message
    msg.setFrom(new InternetAddress(from));
 
    // The recipients can be more than one so we use an array but you can
    // use 'new InternetAddress(to)' for only one address.
    InternetAddress[] address = {new InternetAddress(to)};
    msg.setRecipients(Message.RecipientType.TO, address);
 
    // Set the message subject and date we sent it.
    msg.setSubject("Email from JavaMail test");
    msg.setSentDate(new Date());
 
    // Set message content
    msg.setText("This is the text for this simple demo using JavaMail.");
 
    // Send the message
    Transport.send(msg);
}
catch (MessagingException mex) {
    mex.printStackTrace();
}

Alternatively, instead using:

msg.setText("This is the text for this simple demo using JavaMail.");

you can use next to set the message content:

msg.setContent("This is the text for this simple demo using JavaMail.", "text/plain");

Checking an email address

Here is a little trick to check, using a regular expression, if an email address is well formed:

Pattern rfc2822 = Pattern.compile("^[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?$");
if(rfc2822.matcher(EMAIL_ADDRESS).matches()) {
    // Well formed email
}

Multipart messages

...
// Here create two parts and set as message contect
// Create and fill first part
MimeBodyPart part1 = new MimeBodyPart();
part1.setText("This is part one of this multipart message.");
 
// Create and fill second part
MimeBodyPart part2 = new MimeBodyPart();
part2.setText("This is part two of this multipart message.");
 
// Create the Multipart.
Multipart mp = new MimeMultipart();
mp.addBodyPart(part1);
mp.addBodyPart(part2);
 
// Set the message's content
msg.setContent(mp);
...

Sending attachments

...
// Create a new part for the attached file
MimeBodyPart part3 = new MimeBodyPart();
 
// Put a file in the second part
FileDataSource fds = new FileDataSource("THE_FILE_NAME");
part3.setDataHandler(new DataHandler(fds));
part3.setFileName(fds.getName());
 
// 'mp' is the previously created 'MimeMultipart' object
mp.addBodyPart(part3);
 
// 'msg' is the previously created 'Message' object
msg.setContent(mp);
...

HTML messages

...
MimeBodyPart htmlPart = new MimeBodyPart();
htmlPart.setContent("<h1>Sample</h1><p>This is a sample HTML part</p>", "text/html");
...

Attaching images within the HTML code

...
// Create and fill html part
MimeBodyPart htmlPart = new MimeBodyPart();
htmlPart.setContent("<h1>Sample</h1><p>This is a sample HTML part with an attached image</p>" +
    "<img src='cid:some_image_id'>", "text/html");
 
// Create a new part for the attached image and set the CID image identifier
MimeBodyPart imagePart = new MimeBodyPart();
FileDataSource fds = new FileDataSource("THE_IMAGE_FILE_NAME");
imagePart.setDataHandler(new DataHandler(fds));
imagePart.setHeader("Content-ID", "some_image_id");
 
mp.addBodyPart(htmlPart);
mp.addBodyPart(imagePart);
...

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