Sieve vacation + SRS + forwarded e-mail

[Stuart Henderson]

On 2021-07-09, Saarts, Erik <erik.saarts at vty.ee> wrote:
> We have domain A on cloud, from where mail gets forwarded to our local
> server to domain B. Forwarding is done in
> SPF-compliant way by using SRS (this part we have no control
> over).=C2=A0=C2=A0This SRS address ends up in
> Return-Path header, and sieve vacation replies to=C2=A0this address.
>
>
> This is all absolutely correct, but also useless, as sending mail to
> SRS address leads nowhere.

That's a broken SRS setup then, if it doesn't handle responses to the
sender address there will be some lost mail. Vacation and similar auto
responses are _required_ to reply to the SMTP sender address.