My setup:
Mautic v5
SparkPost Plugin
doctrine queue
I sent newsletter to 30k addresses in a segment. Mautic reports all of them sent. SparkPost shows only ~200. I was sending them in batches of 1k with cron task. Looks like the plugin skipped most of mails during queue processing. Or queue was incorrectly filled.
Queue filled with mautic:broadcasts:send --limit 1000 --no-interaction --no-ansi