Access denied, sending domain

[Palpatine]

After registration I get this mail:

Die Antwort vom Remoteserver ist:
550 5.7.509 Access denied, sending domain [JELLYFIN.ORG] does not pass DMARC verification and has a DMARC policy of reject. [GV1PR10MB8346.EURPRD10.PROD.OUTLOOK.COM 2025-03-30T20:31:07.564Z 08DD6DD2FA8BDDEF] [CH5P223CA0013.NAMP223.PROD.OUTLOOK.COM 2025-03-30T20:31:07.621Z 08DD6FA1C42989E2] [CH1PEPF0000AD74.namprd04.prod.outlook.com 2025-03-30T20:31:07.647Z 08DD65451F13166B]

[TheDreadPirate]

No idea. From what I am reading, it is an over-protective email filter or something like that.