It does if you use a service's SMTP relay. For example, this header is from an email sent via Mailgun SMTP from Hetzner (digits replaced with ): Received: from

It does if you use a service's SMTP relay. For example, this header is from an email sent via Mailgun SMTP from Hetzner (digits replaced with ): Received: from hetzner-dc-ex-* (static.....clients.your-server.de [...]) by mxa.mailgun.org with ESMTP id *; Thu, 06 Feb 2020 17:27:22 -0000 (UTC)