On Mon, Jul 06, 2020 at 07:40:27PM +0000, Drew Tomlinson wrote:
> I use postfix for my own domain and have been forwarding my email to
> outlook.com for years. Recently, email has just been disappearing
> between my server and my inbox so I set it to forward my email to
> gmail.com. Shortly after, I saw some messages like these in the logs:
You're running into intentional breakage caused by SPF and DMARC.
Sadly, this means that (simple) mail forwarding no longer works
reliably.
> In reading Google documentation, I learned SPF is failing. Further
> reading revealed this is a common problem with forwarded email since
> it is not being sent by an authorized IP address. Other articles
> suggested the workaround for this is to change the "Mail From:" to
> reflect my domain since I have SPF configured for it. And maybe this
> is what is meant by SRS (Sender Rewriting Scheme)?
Even changing the envelope sender is not enough. With DMARC you
need to also change the "From:" header in the message.
The simplest thing to do is to encapsulate the original message
as attachment to a new message.
From: <your.address@your.domain.example>
To: <y...@gmail.com>
Subject: forwarded message from: <envelope-sender>
MIME-Version: 1.0
Content-Type: message/rfc822
Return-Path: <envelope-sender>
Received: ...
... original message header ...
... original message body
You'd need to forward your mail to a script that performs the
requisite encapsulation. There are multiple ways to do that.
Nothing directly built-in.
--
Viktor.
