[pfx] Re: Postfix using proxy protocol outbound?

2023-12-18 Thread Wietse Venema via Postfix-users
Wietse; > inside Postfix -reverse haproxy-> remote MTAs in the Internet > That is currently not implemented, and no design exists. Joachim Lindenberg via Postfix-users: > Hello Wietse, > Yes, exactly, no second instance. Ok, implies I haven't overlooked > something. Is this an option you are

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Viktor Dukhovni via Postfix-users
On Tue, Dec 19, 2023 at 12:20:57AM +0100, r.barclay--- via Postfix-users wrote: > > For now, enforcement of pipelining is actually available, while > > enforcement of vs. is still only a hypothetical. > > As an average user without any special or legacy systems, I'd > appreciate if one could

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Wietse Venema via Postfix-users
Wietse: > - Don't accept mail with a broken end-of-data sequence (Postfix > currently allows zero or more followed by ). Or more > generally, don't accept or that aren't part of a > sequence. Postfix does not support BDAT with BINARYMIME, so there > is no valid use of stray or bytes. Vijay

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread r.barclay--- via Postfix-users
> For now, enforcement of pipelining is actually available, while > enforcement of vs. is still only a hypothetical. As an average user without any special or legacy systems, I'd appreciate if one could configure Postfix as safe and secure as possible regarding this issue. So I'd value being

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Viktor Dukhovni via Postfix-users
On Mon, Dec 18, 2023 at 05:40:49PM -0500, Wietse Venema wrote: > > - Postfix 3.8.1, 3.7.6, 3.6.10 and 3.5.20 include the same supporting > > code as 3.9 snapshots, but the "smtpd_forbid_unauth_pipelining" > > parameter defaults to "no". > > Indeed, setting "smtpd_forbid_unauth_pipelining =

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Wietse Venema via Postfix-users
Viktor Dukhovni via Postfix-users: > - Postfix 3.9 (pending official release soon), rejects unuthorised > pipelining by default: "smtpd_forbid_unauth_pipelining = yes". > > - Postfix 3.8.1, 3.7.6, 3.6.10 and 3.5.20 include the same supporting > code as 3.9 snapshots, but the

[pfx] Re: omitting the X-Google-Original-From header

2023-12-18 Thread Steffen Nurpmeso via Postfix-users
Bill Cole via Postfix-users wrote in <6039ed61-2c8f-4a12-b736-994d32632...@billmail.scconsult.com>: |On 2023-12-17 at 09:27:36 UTC-0500 (Sun, 17 Dec 2023 06:27:36 -0800 |(PST)) |saunders.nicholas--- via Postfix-users |is rumored to have said: | |> How is this header populated? |> |>

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Vijay S Sarvepalli via Postfix-users
Hello Wietse, >> - Don't accept mail with a broken end-of-data sequence (Postfix currently allows zero or more followed by ). Or more generally, don't accept or that aren't part of a sequence. Postfix does not support BDAT with BINARYMIME, so there is no valid use of stray or bytes. If

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Wietse Venema via Postfix-users
Bill Cole via Postfix-users: > On 2023-12-18 at 11:31:47 UTC-0500 (Mon, 18 Dec 2023 16:31:47 +) > Vijay S Sarvepalli via Postfix-users > is rumored to have said: > > > Hello Viktor, Wietse, > > (I am copying the Postfix community as the report is out in the public > > now) > > > > First of

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Viktor Dukhovni via Postfix-users
On Mon, Dec 18, 2023 at 02:48:43PM -0500, Bill Cole via Postfix-users wrote: > > This research work has now been published by Sec Consult company, see > > link below . > > It is interesting that they seem to be unaware of some SMTP basics, such as > the fact that message bodies, message headers,

[pfx] Re: mail in SRS-format in destination bypasses postfix rules

2023-12-18 Thread Wietse Venema via Postfix-users
Kristoff via Postfix-users: > Dec 17 04:32:05 smtp postfix/smtp[725772]: 4F58E6A10A0: > to=u...@example.com, > orig_to=SRS0=zxmM=H4=example.com=u...@ourhobbyclubdomain.com, > relay=mail.example.com[A.B.C.D]:25, delay=0.16, delays=0.05/0/0.08/0.02, > dsn=2.0.0, status=sent (250 2.0.0 Ok: queued

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Bill Cole via Postfix-users
On 2023-12-18 at 11:31:47 UTC-0500 (Mon, 18 Dec 2023 16:31:47 +) Vijay S Sarvepalli via Postfix-users is rumored to have said: Hello Viktor, Wietse, (I am copying the Postfix community as the report is out in the public now) First of all thank you for your help and response to highlight

[pfx] Re: Postfix authenticated sender and From: header verification

2023-12-18 Thread Vijay S Sarvepalli via Postfix-users
Hello Viktor, Wietse, (I am copying the Postfix community as the report is out in the public now) First of all thank you for your help and response to highlight your approach to this issue. This may not be the first time you have observed types of abuse that relate to spoofing. This research

[pfx] Re: mail in SRS-format in destination bypasses postfix rules

2023-12-18 Thread Matus UHLAR - fantomas via Postfix-users
On 18.12.23 13:52, Kristoff via Postfix-users wrote: Yes, I guess it are spam or phishing mails. The trick with  "smtpd_recipient_restrictions" looks interesting. Thanks! As I understand it now, there are three steps in this: 1/ the spammer sends us an email with destination

[pfx] Re: Postfix using proxy protocol outbound?

2023-12-18 Thread Joachim Lindenberg via Postfix-users
Hello Wietse, Yes, exactly, no second instance. Ok, implies I haven´t overlooked something. Is this an option you are willing to consider? The key benefit to guys like me is that one doesn´t have to manage two instances, considering setup and maintenance, configuration (like tls policies),

[pfx] Re: mail in SRS-format in destination bypasses postfix rules

2023-12-18 Thread Kristoff via Postfix-users
Hi Matus, Thanks. Yes, I guess it are spam or phishing mails. The trick with  "smtpd_recipient_restrictions" looks interesting. Thanks! As I understand it now, there are three steps in this: 1/ the spammer sends us an email with destination

[pfx] Re: Postfix using proxy protocol outbound?

2023-12-18 Thread Wietse Venema via Postfix-users
Did you mean instead of inside Postix -> outside Postfix -> remote MTAs in the Internet Use inside Postfix -reverse haproxy-> remote MTAs in the Internet Theat is currently not implemented, and no design exists. Wietse ___

[pfx] Re: mail in SRS-format in destination bypasses postfix rules

2023-12-18 Thread Matus UHLAR - fantomas via Postfix-users
On 17.12.23 23:12, Kristoff via Postfix-users wrote: I don't know if this question has already been ask, but I did not find anything in the archive of the mailing-list. I co-manage a postfix-server for an hobby-club. We provide email-addresses to our members, which are linked to aliases, so

[pfx] Postfix using proxy protocol outbound?

2023-12-18 Thread Joachim Lindenberg via Postfix-users
I am running my postfix (mailcow) in my local network and interface to the outside via a VPN that is terminated on a VPS with a static address with adequate reputation. Historically I used NAT in both directions in- and outbound, but I switched to use proxy protocol inbound as I am in fact now