On Fri, 28 Jun 2019 at 14:48, Viktor Dukhovni <postfix-us...@dukhovni.org> wrote:
> On Fri, Jun 28, 2019 at 10:26:20AM +0200, Matus UHLAR - fantomas wrote: > > > >My question now is: What is the correct/expected behaviour in such a > > >situation? > > > > You apparently should use SRS when forwarding mail. That will change > sender > > to your domain so the mail will pass SPF and should not be refused by > google. > > SRS is enough to avoid trouble with SPF, but not enough to avoid > trouble with DMARC. Email forwarding has been irreparably broken > by DMARC. > Where the original rejected-by-Gmail email appears good my approach (automated) is to attach it to a new email to the recipient (with Reply-To: set to the original From: header). The body of the new email is a short text explaining to recipient what has happened. And rewrite the [45]nn [45].n.n response from Gmail to 250 2.0.0 so that the sender isn't wrongly informed that the email couldn't be delivered. It's a kludge but it works well enough (and instances are pretty rare).
