>When I try to reply his message in my mail client, it received the following error message: > Delivery to xxx@outlook.com failed with error: outlook-com.olc.p

>When I try to reply his message in my mail client, it received the following error message: > Delivery to xxx@outlook.com failed with error: outlook-com.olc.protection.outlook.com. said:... He got error messages? I get mail silently dropped. MS drops mail from my reputable mail servers - and from rep svs that send mail to MS accts I manage.