A couple of email addresses on my OpenBSD server are forwarded to microsoft domains. For quite some time; this has worked flawlessly. Recently something changed. Now, an email sent from sendgrid.com to my server results in a bounced message from outlook.com with this error.
received-spf: Fail (protection.outlook.com: domain of u3352509.wl010.sendgrid.net does not designate 64.140.xxx.yyy as permitted sender) receiver=protection.outlook.com; client-ip=64.140.xxx.yyy; helo= myserver.ca; Where xxx,yyy & myserver hide real values. It seems outlook.com believes my server is "sending" email for sendgrid; whereas originating server is valid and my server is just forwarding. Anyone else encounter this situation; is there a way to resolve this?
