XWIKI-16309. I think there was a misunderstanding that BlockingQueue.offer() doesn't throw an InterruptedException when the queue is full and the timeout has passed (instead it just returns false).
- is caused by
XWIKI-16309 PrepareMailQueueManager use an infinite queue
- is related to
XWIKI-20518 "IllegalStateException: Queue full" exception in the logs when too many emails to send