Forum Discussion
Exchange Online Protection SPF record
Hi, I have received a message sent via Exchange Online host IPv6 "2603:10a6:20b:c0::31". The message was marked as spam because of SPF fail. Subnet "2603:10a6:20b:c0::/64" is not in the list of O365 ...
The issue is still there. Emails from our tenant are sent from 2603:10a6:800:16f::8 which is not listed in spf.protection.outlook.com.
FYI: It sounds like this is by design / due to those mails not exitting Outlook's infrastructure. There's more detail on this here: https://serverfault.com/a/1154098/137255
It's definitely frustating that the rules aren't consistent, especially as it relies on knowledge of custom MS mail headers if you're using a custom mail client to verify the received mails; but it seems to be legit.