java - Spring Boot 1.2.5.RELEASE - Sending E-mail via Gmail SMTP

Question

Firstly, I need to say that sending email with 1.2.0.RELEASE works fine

application.properties:

spring.mail.host = smtp.gmail.com
spring.mail.username = *****@gmail.com
spring.mail.password = ****
spring.mail.properties.mail.smtp.auth = true
spring.mail.properties.mail.smtp.socketFactory.port = 465
spring.mail.properties.mail.smtp.socketFactory.class = javax.net.ssl.SSLSocketFactory
spring.mail.properties.mail.smtp.socketFactory.fallback = false

pox.xml

<parent>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-parent</artifactId>
     <version>1.2.0.RELEASE</version>
     <relativePath/>
</parent>

.......

<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<dependency>
     <groupId>org.springframework.boot</groupId>
     <artifactId>spring-boot-starter-mail</artifactId>
</dependency>

After changing parent version to 1.2.5.RELEASE email sending hasn't worked

Docs says: If spring.mail.host and the relevant libraries (as defined by spring-boot-starter-mail) are available, a default JavaMailSender is created if none exists.

So i've added

<dependency>
    <groupId>javax.mail</groupId>
    <artifactId>mail</artifactId>
    <version>1.4.7</version>
</dependency>

It hasn't helped and then i've replaced it to

<dependency>
    <groupId>com.sun.mail</groupId>
    <artifactId>javax.mail</artifactId>
    <version>1.5.4</version>
</dependency>

Also i've tried

spring.mail.host = smtp.gmail.com
spring.mail.username = *****@gmail.com
spring.mail.password = ****
spring.mail.port = 465

Result the same.

It's not a problem to create and configure @Bean manually. But I want to use all beauty of Spring Boot.
Please point me to my mistakes.

Thanks in advance

Answer 1

It looks like there's a regression/behaviour change in Java Mail. The change is in both 1.5.3 and 1.5.4. Your app works with Boot 1.2.0 as it uses Java Mail 1.5.2. It fails with Boot 1.2.5 as it uses Java Mail 1.5.4.

The problem in 1.5.3+ appears to be that the SMTP transport connects on port 465 and GMail expects an SSL handshake. Java Mail incorrectly thinks it's not using SSL so it never initiates the handshake and the connection attempt (eventually) times out. You can convince Java Mail to do the right thing by being explicit about the use of SSL. Add the following to application.properties:

spring.mail.properties.mail.smtp.ssl.enable = true