They are likely forwarding to a CRM system and the MTA of the CRM system is picky with authentication of forwarded emails or is likely scoring it high due to said authentication failures...
Sent from my iPad > On Aug 26, 2025, at 10:07 PM, Uwe Arnold via mailop <mailop@mailop.org> wrote: > > Hi guys, > > this is my first email here. > In a private matter I used the reply button on some Lufthansa Feedback topic. > > Then I got a Office 365 rejection. > > Status code: 550 5.7.1 > > Sender Address: > customer.relations+SRS=mcOit=3G=itnomad.de=uwe.arn...@lufthansa.com > Recipient Address: customer.relati...@lufthansa.com > > Error Details > Error: 550-5.7.1 This email was rejected because it violates our security > policy. 550 5.7.1 Die digitale Signatur der E-Mail ist ung?ltig. > Message rejected by: mail.alpha-com.de > > Notification Details > Sent by: FRWPR09MB7955.eurprd09.prod.outlook.com > > Would be great if you could refer me to the correct mail admins. this doesn't > look right. > > Best regards, > Uwe > <OpenPGP_0xD98AF46B4CA8C71D.asc> > _______________________________________________ > mailop mailing list > mailop@mailop.org > https://list.mailop.org/listinfo/mailop _______________________________________________ mailop mailing list mailop@mailop.org https://list.mailop.org/listinfo/mailop
