Simple Python script as SMTP server for outgoing e-mails?

[Chris Angelico]

On Tue, Jul 23, 2013 at 7:19 PM, Chris Angelico <rosuav at gmail.com> wrote:
> Ah, there's a solution to this one. You simply use your own
> envelope-from address; SPF shouldn't be being checked for the From:
> header.

There's an example, by the way, of this exact technique right here -
python-list at python.org sends mail to me with an envelope-from of
"python-list-bounces+rosuav=gmail.com at python.org" - which passes SPF,
since python.org has a TXT record designating the sending IP as one of
theirs. It doesn't matter that invalid.invalid (your supposed domain)
doesn't have an SPF record, nor would it be a problem if it had one
that said "v=spf1 -all", because that domain wasn't checked. Mailing
lists are doing the same sort of forwarding that you're doing.

(Apologies to those who read this as a newsgroup, for whom this won't
be as parallel an example. But it's still the case, just not for the
posts you receive.)

ChrisA