JAMES-3876 Load-balancing flag for Remote Delivery Gateways

[AdBuch]

Implement round robin loadbalancing if multiple gateways are defined
Add new Remote Delivery property loadBalancing.

[chibenwa]

Nice contribution!

We need to document the new configuration option...

• https://github.com/apache/james-project/blob/master/server/apps/distributed-app/docs/modules/ROOT/partials/RemoteDelivery.adoc

• james-project/server/mailet/mailets/src/main/java/org/apache/james/transport/mailets/RemoteDelivery.java

  Line 51 in 5a57af8

  /**

  (Java Doc)

Can you add the documentation to this PR?

[AdBuch]

Documentation is added, is there a way for me to retrigger the pipeline?
You know which tests are failing? I could put some effort in it to make them more stable. or just autorerun them.

[chibenwa]

Documentation is added, is there a way for me to retrigger the pipeline?

For you, no, for me, yes.

You know which tests are failing? I could put some effort in it to make them more stable. or just autorerun them.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.22.2:test (default-test) on project james-server-webadmin-data: There was a timeout or other error in the fork -> [Help 1]

Known. Port binding issue. I retriggered a build.

[chibenwa]

Thanks for the contribution!