[Rails] How to set 'Return-Path' in ActionMailer to avoid SPF failure?

[Stian Grytøyr]

Stian Grytøyr <sgrytoyr at gmail.com> wrote:

> I may have misread OP, but I got the impression that he needed to
> set the Return-Path to something different from the envelope sender
> address. In that case, you'd need to configure the MTA to _not_ set
> the Return-Path to the same as the envelope sender address.

I need to correct myself here. It is not possible to have a Return-Path
that is different from the envelope sender address, no matter how much
you configure the local MTA. At least that's my conclusion after discussing 
this with Guan off-list.

SPF uses the envelope sender address to determine whether or not
the mail should pass. The Return-Path header is then added by the 
last MTA. My tests seem to confirm this. There is no Return-Path in 
the headers as the mail goes over the network from the originating MTA 
to the recipient's MTA.

-- 
Regards,
Stian Grytøyr