The following message to sheronsebastiampillai@outlook.de 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 [LOBP123MB8168.GBRP123.PROD.OUTLOOK.COM 2026-03-03T07:15:07.625Z 08DE78DAEE8A399D] [DUZPR01CA0294.eurprd01.prod.exchangelabs.com 2026-03-03T07:15:03.752Z 08DE78A060CAECFD] [DU6PEPF0000952A.eurprd02.prod.outlook.com 2026-03-03T07:15:07.645Z 08DE762E63DEE0B9]"