We're using Mailgun to send promotional email messages, and we have a separate subdomain set up for that purpose (mail.example.com
). This domain is also specified in the Sender
header.
On the other hand, the address in the From
header uses an example.com
domain.
This works fine on the majority of major email providers, but Outlook has decided not to use the display name and address specified in the From
header and replaces it with news=example.com@mail.example.com <news=example.com@mail.example.com> on behalf of News <news@example.com>
. This looks... less than professional.
I understand it would raise suspicion if the domains were completely different, but in our case, one is a subdomain of the other.
Is this behavior described somewhere in the RFC, or is it just Microsoft's policy? Are there any workarounds, besides changing the Sender
or From
domains?