How to force JavaMailSenderImpl to use TLS1.2?

Question

Have a JDK7 app running on Tomcat and it does have the following env settings:

-Dhttps.protocols=TLSv1.1,TLSv1.2 

The above setting ensures that we don't use TLS 1.0 when connecting over HTTPS while making API calls etc.

We also use the org.springframework.mail.javamail. JavaMailSenderImpl class to send outgoing SMTP email, and use these props:

 mail.smtp.auth=false;mail.smtp.socketFactory.port=2525;mail.smtp.socketFactory.fallback=true;mail.smtp.starttls.enable=true

The problem is that the connection to the SMTP email server is failing when it's upgraded to TLS1.2.

javax.net.ssl.SSLHandshakeException: Remote host closed connection during handshake

Is there a settings or code change that will force the TLS1.2 protocol?

I did some searching and it looks like these env settings are only for applet and web clients, not for server side apps

-Ddeployment.security.SSLv2Hello=false -Ddeployment.security.SSLv3=false -Ddeployment.security.TLSv1=false

Answer 1

This is the fix for the next guy looking:

mail.smtp.starttls.enable=true;
mail.smtp.ssl.protocols=TLSv1.2;

Answer 2

It didn't work for me in one pretty old app and I couldn't realize why. After some research I found that the javax.mail version in the app dependencies was 1.4. You must upgrade to at least 1.5.

Answer 3

An update to the most recent version (1.6.2.) of Java Mail also fixes the issue. In my case I upgraded from:

<dependency>
    <groupId>javax.mail</groupId>
    <artifactId>mail</artifactId>
    <version>1.5.0-b01</version>
</dependency>

to:

<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>javax.mail</artifactId>
    <version>1.6.2</version>
</dependency>

This fixed the error

javax.mail.AuthenticationFailedException: 421 4.7.66 TLS 1.0 and 1.1 are not supported. Please upgrade/update your client to support TLS 1.2

I was getting from an Outlook SMTP-Server. No property changes needed.

Answer 4

I needed both Vojtech Zavrel and Sunny's answer in my case. I was running Java 1.8 Spring Boot 1.2.5 and running on Big Sur 11.2.3 and spring version 4.2.1.RELEASE.

After I updated my dependency like this

<dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mail</artifactId>
        <version>1.5.0-b01</version>
</dependency>

and I updated my JavaMailSenderImpl with

Properties prop = new Properties();
prop.setProperty("mail.smtp.auth", "true");
prop.setProperty("mail.smtp.starttls.enable", "true");
prop.setProperty("mail.smtp.ssl.protocols", "TLSv1.2"); // Added this line
prop.setProperty("mail.smtp.ssl.trust", mailUri.getHost());
mailSender.setJavaMailProperties(prop);

I saw the Received fatal alert: protocol_version error resolve.