The following message to zcekiz@hotmail.com was undeliverable. The reason for the problem: 5.3.0 - Other mail system problem 550-"5.7.515 Access denied, sending domain LISTS.FSMPI.RWTH-AACHEN.DE doesn't meet the required authentication level. The sender's domain in the 5322.From address doesn't meet the authentication requirements defined for the sender. To learn how to fix this see: https://go.microsoft.com/fwlink/p/?linkid=2319303 Spf= Pass , Dkim= Fail , DMARC= Pass [VE1P190MB0815.EURP190.PROD.OUTLOOK.COM 2026-05-12T06:15:16.916Z 08DEAFBE74FFE384] [SI2PR06CA0002.apcprd06.prod.outlook.com 2026-05-12T06:15:17.008Z 08DEAFC7F21B9E16] [OSA0EPF000000C9.apcprd02.prod.outlook.com 2026-05-12T06:15:17.029Z 08DEADCA55B11EEB]"