How to send emails via Gmail SMTP in an Android app?

Other Questions Gmail
1

I’m having trouble setting up email sending for my Android app using Gmail’s SMTP service. I’m using JavaMail with several jars including activation.jar, additional.jar, and mail.jar. I need help understanding what might be causing a connection error.

Here’s a new example of my code:

private void sendEmail() {
    String senderEmail = "[email protected]";
    String senderPassword = "mypassword";
    String recipientEmail = "[email protected]";
    String subject = "Test Subject";
    String body = "Hello, this is a test email.";

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

    Session session = Session.getInstance(props, new Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(senderEmail, senderPassword);
        }
    });

    try {
        Message message = new MimeMessage(session);
        message.setFrom(new InternetAddress(senderEmail));
        message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipientEmail));
        message.setSubject(subject);
        message.setText(body);
        Transport.send(message);
    } catch (MessagingException e) {
        e.printStackTrace();
    }
}

I keep seeing a connection timeout error when trying to connect to smtp.gmail.com. Has anyone seen this issue and can offer advice on how to resolve it?

2

hey there! have u tried using a different email service? sometimes gmail can be tricky. I’ve had good luck with sendgrid for my android apps. its pretty easy to set up and they have a free tier. might be worth checkin out if ur still havin issues with gmail smtp

3

I’ve dealt with similar SMTP issues in Android apps before. One key thing to check is whether you’re running this code on the main thread. Network operations like sending emails should always be done on a background thread to avoid ANR (Application Not Responding) errors.

Try wrapping your email sending logic in an AsyncTask or using Java’s ExecutorService. Also, make sure you’ve added the INTERNET permission to your AndroidManifest.xml file.

Another common pitfall is using your regular Gmail password. Google now requires you to use an App Password for less secure apps. Go to your Google Account settings, enable 2-Step Verification, then generate an App Password specifically for your Android app.

Lastly, double-check your firewall settings. Some networks block outgoing connections on port 587. You might need to switch to port 465 and use SSL instead of TLS:

props.put(“mail.smtp.socketFactory.port”, “465”);
props.put(“mail.smtp.socketFactory.class”, “javax.net.ssl.SSLSocketFactory”);

Hope this helps troubleshoot your connection issues!

4

I encountered a similar issue when implementing email functionality in my Android app. One crucial step I overlooked was adding the necessary network security configuration. In your app’s res/xml directory, create a file named network_security_config.xml with the following content:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
    <base-config cleartextTrafficPermitted="true" />
</network-security-config>

Then, in your AndroidManifest.xml, add this line within the tag:

android:networkSecurityConfig=“@xml/network_security_config”

This configuration allows cleartext traffic, which might be necessary for some SMTP connections. Remember to consider the security implications and use proper encryption in production.

Also, ensure you’re handling exceptions properly and logging any errors for better debugging. Good luck with your implementation!