Cannot use Greenmail with Spring Boot 3

[bodiam]

Hi all,

I'm currently affected by this issue: spring-projects/spring-boot#33452

I also have this problem with Spring Boot 3 and Greenmail, but I'm using Greenmail Alpha 3, and the only dependency I have depending on com.sun.activation:jakarta.activation:2.0.1 is Greenmail:

+--- com.icegreen:greenmail-junit5:2.0.0-alpha-3
|    +--- com.icegreen:greenmail:2.0.0-alpha-3
|    |    +--- com.sun.mail:jakarta.mail:2.0.1
|    |    |    \--- com.sun.activation:jakarta.activation:2.0.1
|    |    +--- jakarta.activation:jakarta.activation-api:2.0.1 -> 2.1.0
|    |    +--- org.slf4j:slf4j-api:1.7.36 -> 2.0.4
|    |    \--- junit:junit:4.13.2 (*)
|    \--- org.junit.jupiter:junit-jupiter-api:5.9.1 (*)

Shouldn't Greenmail stop depending on this? (I thought that was the main reason to use Greenmail 2.0?)

[marcelmay]

@bodiam , try to exclude the transitive dependency on com.sun.activation:jakarta.activation.

GreenMail depends on Jakarta Mail, which again brings along jakarta.activation implementation of com.sun.activation:jakarta.activation.

Spring Boot 3 brings along jakarta.activation implementation of org.eclipse.angus:angus-activation, pulled in by Angus Mail .

So you have to exclude one of them, to avoid conflict from having two implementations.

Exclude either angus-activation ...

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-mail</artifactId>
    <exclusions>
        <exclusion>
            <groupId>org.eclipse.angus</groupId>
            <artifactId>angus-activation</artifactId>
        </exclusion>
    </exclusions>
</dependency>

... or (old Jakarta Mail 2.x) com.sun.mail implementation:

<dependency>
    <groupId>com.icegreen</groupId>
    <artifactId>greenmail-junit5</artifactId>
    <version>2.0.0-alpha-3</version>
    <scope>test</scope>
    <exclusions>
        <exclusion>
            <groupId>com.sun.mail</groupId>
            <artifactId>jakarta.mail</artifactId>
        </exclusion>
    </exclusions>
</dependency>

For a Spring Boot 3 application, I'd recommend to exclude GreenMails com.sun.mail:jakarta.mail .

Migrating GreenMail to Angus-Mail 2.1 is work-in-progress and planned for GreenMail 2.1 (version parity with Jakarta Mail 2.1).

[marcelmay]

Example: https://github.com/greenmail-mail-test/greenmail-example-spring-boot-3

[bodiam]

@marcelmay Thanks for the example and the explanation. I was under the impression that alpha-3 would already have fixed this. For the time being, I added this to my build.gradle.kts:

configurations.all {
    resolutionStrategy {
        exclude("com.sun.activation", "jakarta.activation")
    }
}