3 ms·
If Microsoft is adding an Authentication-Results header to outbound email where the receiver address is used in the header, then this is a bad bug. Authenticat
by LeonM 5y ago
If Microsoft is adding an Authentication-Results header to outbound email where the receiver address is used in the header, then this is a bad bug.
Authentication-Results are not supposed to be added by the sender anyway, and it should be used to verify the sender (from) address, not the receiver address.
Again, I wasn't able to reproduce this bug. When sending from o365 to Gmail the Authentication-Results is added by Gmail, not by o365.
Email receivers are not supposed to overwrite headers (as this can also break DKIM signatures), they should only add headers. So I highly doubt that is happening.
- bouke 5y agoI agree that it shouldn't happen. But it does, I've reproduced the issue with different recipients. Send a message having only A and B as bcc. The header of the message received by B contains the domain name of recipient A.