Caused by: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection? - email

Question

I am getting the following error when setting up an email service with spring boot while trying to connect to round cube:
Caused by: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
This leads me to think roundcude is not using a SSL connection and I should not use port 143. Therefore I try and use port 25, but I get the following error when I do.
Caused by: javax.net.ssl.SSLException: Unrecognized SSL message, plaintext connection?
application.properties
#email setup
spring.mail.host = mail.email address.com
spring.mail.username = email address
spring.mail.password = my password
spring.mail.properties.mail.smtp.auth= true
spring.mail.port = 25 or port 145
spring.mail.properties.mail.smtp.socketFactory.class= javax.net.ssl.SSLSocketFactory
spring.mail.properties.mail.smtp.socketFactory.fallback= false
spring.mail.properties.mail.smtp.ssl.enable = true
Email service
#Component
public class EmailServiceImpl implements EmailService {
#Autowired
private JavaMailSender javaMailSender;
#Override
public void sendEmail(String toAddress, String fromAddress,
String subject, String body) {
SimpleMailMessage simpleMailMessage = new SimpleMailMessage();
simpleMailMessage.setFrom(fromAddress);
simpleMailMessage.setTo(toAddress);
simpleMailMessage.setSubject(subject);
simpleMailMessage.setText(body);
javaMailSender.send(simpleMailMessage);
}
}
I looked at roundcube's documentation and apparently is uses port 143 so this is rather confusing. This making me think I am setting this up wrong.
I also tried gmail but since I have a two factor authentication I ran into more issue so I decided to use roundcube which is what I would rather use anyway.
Advice?

Answer 1

It seems you're trying to connect to SMTP using non-secure ports. Usually secure ports would be 587 or 465.
This is the configuration that works for me to send e-mail using GMail:
spring.mail.host=smtp.gmail.com
spring.mail.port=587
spring.mail.username=my-email#gmail.com
spring.mail.password=my-password
spring.mail.properties.mail.smtp.auth = true
spring.mail.properties.mail.smtp.starttls.enable = true
spring.mail.properties.mail.smtp.socketFactory.class = javax.net.ssl.SSLSocketFactory
spring.mail.properties.mail.smtp.connectiontimeout = 60000
spring.mail.properties.mail.smtp.timeout = 60000