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 [CW1P123MB8613.GBRP123.PROD.OUTLOOK.COM 2026-03-01T16:16:47.359Z 08DE77334B24196D] [AS9PR05CA0184.eurprd05.prod.outlook.com 2026-03-01T16:16:46.830Z 08DE77742DA8021F] [AMS0EPF000001A4.eurprd05.prod.outlook.com 2026-03-01T16:16:47.371Z 08DE758865613214]"