Re: Fwd: Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread Viktor Dukhovni
On Tue, Aug 23, 2022 at 01:13:56AM -0400, Demi Marie Obenour wrote: > You should definitely deploy DNSSEC, but only after you are able to > deploy it properly. That means having procedures to avoid nasty DNSSEC- > related downtime. That's needlessly scary and non-specific. Rather, it means,

Re: bagels

2022-08-22 Thread Ansgar Wiechers
On 2022-08-22 Ruben Safir wrote: > On Mon, Aug 22, 2022 at 08:50:51AM +0200, Ansgar Wiechers wrote: >> You could use a check_sender_access restriction with a regular >> expression like this: >> >> /bagel/ REJECT > > Do I use the map created by the postfix/access file for this? Depends on your

Re: Fwd: Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread Demi Marie Obenour
On 8/22/22 17:38, nate wrote: > On 2022-08-22 14:30, Viktor Dukhovni wrote: > >> Correct, because there's no point. Mail would be sent whether the >> certificate is trusted or not, and whether or not the DNS-ID matches >> expectations. >> >> Setting up a TLS policy for each domain that's hosted

Re: Strange thing in Postfix log?

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 11:42:38PM +0200, Jaroslaw Rafa wrote: > Hello, > this just appeared in my Postfix log: > > Aug 22 23:35:50 rafa postfix/smtpd[28891]: connect from unknown[unknown] > Aug 22 23:35:50 rafa postfix/smtpd[28891]: lost connection after CONNECT from > unknown[unknown] > Aug 22

Re: Fwd: Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 02:38:20PM -0700, nate wrote: > On 2022-08-22 14:30, Viktor Dukhovni wrote: > > > Correct, because there's no point. Mail would be sent whether the > > certificate is trusted or not, and whether or not the DNS-ID matches > > expectations. > > > > Setting up a TLS policy

Strange thing in Postfix log?

2022-08-22 Thread Jaroslaw Rafa
Hello, this just appeared in my Postfix log: Aug 22 23:35:50 rafa postfix/smtpd[28891]: connect from unknown[unknown] Aug 22 23:35:50 rafa postfix/smtpd[28891]: lost connection after CONNECT from unknown[unknown] Aug 22 23:35:50 rafa postfix/smtpd[28891]: disconnect from unknown[unknown] I

Re: Fwd: Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread nate
On 2022-08-22 14:30, Viktor Dukhovni wrote: Correct, because there's no point. Mail would be sent whether the certificate is trusted or not, and whether or not the DNS-ID matches expectations. Setting up a TLS policy for each domain that's hosted by Microsoft is unrealistic, and they don't

Re: Fwd: Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 02:09:26PM -0700, nate wrote: > postfix/smtp[7329]: Untrusted TLS connection established to > example-com.mail.protection.outlook.com[104.47.55.110]:25: TLSv1.2 with > cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits) > > I assume it says Untrusted because Postfix

Fwd: Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread nate
On 2022-08-22 13:55, Viktor Dukhovni wrote: This should be the full certificate chain, not just the lead certificate. For that, you need at least: smtp_tls_security_level = may or perhaps (given a local validating resolver and only loopback nameserver IPs in /etc/resolv.conf or

Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 01:41:35PM -0700, nate wrote: > More recently I formalized this configuration even more in an attempt to > make my system more up to date, being able to send and receive with > TLS. > > This is my TLS related configuration > [..] > smtpd_sasl_tls_security_options =

Re: Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread Jaroslaw Rafa
Dnia 22.08.2022 o godz. 13:41:35 nate pisze: > > What I am confused by is Postfix does not appear to be attempting > to use TLS on any outbound emails. I have tested with Gmail and > with MS Office 365. Sample tcpdump Your config contains TLS settings for inbound (stmpd_tls_...) but I don't see

Postfix 3.5 and outbound TLS/SSL

2022-08-22 Thread nate
Hello list Been using postfix for over 20 years now, though haven't really spent much time on the SSL end of things for it. A few years ago I setup SSL for inbound mainly for SASL auth sending that has worked fine. More recently I formalized this configuration even more in an attempt to

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 01:51:59PM -0400, Demi Marie Obenour wrote: > The correct solution to prevent email forgery is DNSSEC + DKIM + > DMARC with p=reject + some way to prevent DMARC from accepting based > on SPF alone. In practice, lots of stuff is misconfigured. I don’t > run a mail server,

Re: bagels

2022-08-22 Thread Ruben Safir
On Mon, Aug 22, 2022 at 08:50:51AM +0200, Ansgar Wiechers wrote: > On 2022-08-21 Ruben Safir wrote: > > any way I can block all bagels using access > > > > 2022-08-09T22:38:19.695815-04:00 www2 postfix/qmgr[31914]: 2251E16403D: > > from=, > > size=9363, nrcpt=1 (queue active) > >

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Bill Cole
On 2022-08-22 at 13:18:25 UTC-0400 (Mon, 22 Aug 2022 13:18:25 -0400) is rumored to have said: Viktor, genuine question and not meant to be combative; I feel like I'm forgetting / missing something. Why isn't every spammer sending spam from <> if it gets a free pass? As Viktor said,

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Demi Marie Obenour
On 8/22/22 12:17, Phil Stracchino wrote: > On 8/22/22 11:50, Viktor Dukhovni wrote: >> On Mon, Aug 22, 2022 at 05:35:54PM +0200, Patrick Proniewski wrote: >>> But the "loophole" here is that blank sender/return-path is allowed >>> (MAILER DAEMON), I could prohibit that, but with huge caveats. >>

Re: bagels

2022-08-22 Thread Ruben Safir
On Mon, Aug 22, 2022 at 08:50:51AM +0200, Ansgar Wiechers wrote: > On 2022-08-21 Ruben Safir wrote: > > any way I can block all bagels using access > > > > 2022-08-09T22:38:19.695815-04:00 www2 postfix/qmgr[31914]: 2251E16403D: > > from=, > > size=9363, nrcpt=1 (queue active) > >

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 01:18:25PM -0400, post...@ptld.com wrote: > Viktor, genuine question and not meant to be combative; > > I feel like I'm forgetting / missing something. > Why isn't every spammer sending spam from <> if it gets a free pass? It doesn't get a "free pass", but it correctly

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread postfix
Viktor, genuine question and not meant to be combative; I feel like I'm forgetting / missing something. Why isn't every spammer sending spam from <> if it gets a free pass?

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 12:17:52PM -0400, Phil Stracchino wrote: > A lot of the problems in spam filtering is that the protocols we use for > email delivery were fundamentally designed in insecure, unauthenticated > ways, because they were created in a different, friendlier, arguably > more

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Phil Stracchino
On 8/22/22 11:50, Viktor Dukhovni wrote: On Mon, Aug 22, 2022 at 05:35:54PM +0200, Patrick Proniewski wrote: But the "loophole" here is that blank sender/return-path is allowed (MAILER DAEMON), I could prohibit that, but with huge caveats. Best to ignore bad advice. You may need a better

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Viktor Dukhovni
On Mon, Aug 22, 2022 at 05:35:54PM +0200, Patrick Proniewski wrote: > > On 22 Aug 2022, at 17:20, post...@ptld.com wrote: > > > > This isn't the complete answer to your problem, but one of the puzzle > > pieces that might help your situation. > > > >smtpd_recipient_restrictions =

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread Patrick Proniewski
Hi, I'm already using: smtpd_sender_restrictions = reject_unlisted_sender, check_sender_access hash:/etc/postfix/sender_access reject_unknown_sender_domain, reject_non_fqdn_sender, permit But the "loophole" here is that blank sender/return-path is

Re: filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread postfix
This isn't the complete answer to your problem, but one of the puzzle pieces that might help your situation. smtpd_recipient_restrictions = reject_non_fqdn_sender http://www.postfix.org/postconf.5.html#reject_non_fqdn_sender We have received a big batch of phishing emails that was

filtering incoming email mail_from/reply to/from/etc.

2022-08-22 Thread patpro
Hello, We have received a big batch of phishing emails that was not properly detected (hence not blocked). They all shared a special characteristic: To: Recipients From: Administrateur Reply-To: Return-Path: <> To and From are not qualified email addresses, Reply-To is bogus but qualified

Re: bagels

2022-08-22 Thread Ansgar Wiechers
On 2022-08-21 Ruben Safir wrote: > any way I can block all bagels using access > > 2022-08-09T22:38:19.695815-04:00 www2 postfix/qmgr[31914]: 2251E16403D: > from=, > size=9363, nrcpt=1 (queue active) > 2022-08-09T22:39:09.275352-04:00 www2 postfix/qmgr[31914]: ECA0316403D: > from=, >