Steps to reproduce

1. Register 7000 users via the PUR-Module
2. Send about 500 Messages via info.magnolia.ui.framework.message.MessagesManager.broadcastMessage(Message)

Expected results

Magnolia should still be running normally.

Actual results

During startup (for about half an hour) and when a User interacts with the messages workspace (also for about 10-30 minutes), the author is completely unresponsive.

Workaround

Script to delete all messages to PUR-Users in the messages workspace.

Development notes

A colleague wrote a module that daily sends messages via broadcastMessage to all users. This might be a mistake, but in my opinion it  should generally not be possible to send messages to PUR-Users. Also the messages workspace is never being cleaned up. It would be nice to have at least the possibility to configure that messages older than a certain date are being deleted or if there are a million messages in the workspace they will be cleaned up automatically.