2024-02-27 00:20 UTC incoming mails to mu21 started to be delayed
2024-02-27 00:30 UTC incoming mails to mu21 were routed through our secondary mail servers
2024-02-27 06:20 UTC cause has been identified (misconfiguration during an update) and fixed
2024-02-27 10:30 UTC analysis has shown that no one was affected.