[pfx] Re: body_checks not catching all backscatter

Sebastian Wiesinger via Postfix-users wrote > Thanks Peter but I will never ever, as long as I live, use anything > connected to UCEProtect. +1 Regards, Michael ___ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email

[pfx] Re: body_checks not catching all backscatter

* Peter via Postfix-users [2023-05-03 07:45]: > On 28/04/23 03:59, Sebastian Wiesinger via Postfix-users wrote: > > Hi everyone, > > > > I'm not sure if I'm missing something but I can't find out why my > > body_checks doesn't catch all the backscatter I'm gett

[pfx] Re: body_checks not catching all backscatter

May 3, 2023 at 4:26 PM, "Matus UHLAR - fantomas via Postfix-users" wrote: > > > > > > > > > On 28/04/23 03:59, Sebastian Wiesinger via Postfix-users wrote: > > > > I'm not sure if I'm missing something but I can't find out why my > >

[pfx] Re: body_checks not catching all backscatter

On 28/04/23 03:59, Sebastian Wiesinger via Postfix-users wrote: > I'm not sure if I'm missing something but I can't find out why my > body_checks doesn't catch all the backscatter I'm getting right now. May 3, 2023 at 1:43 PM, "Peter via Postfix-users" wrote: I've found t

[pfx] Re: body_checks not catching all backscatter

On 3/05/23 17:51, Ken Peng via Postfix-users wrote: But anybody can use our (even setup correctly) mailserver as backscatter source? Not if you configure postfix properly. Peter ___ Postfix-users mailing list -- postfix-users@postfix.org

[pfx] Re: body_checks not catching all backscatter

May 3, 2023 at 1:43 PM, "Peter via Postfix-users" wrote: > > On 28/04/23 03:59, Sebastian Wiesinger via Postfix-users wrote: > > > > > Hi everyone, > > I'm not sure if I'm missing something but I can't find out why my > > body_checks doesn't catc

[pfx] Re: body_checks not catching all backscatter

On 28/04/23 03:59, Sebastian Wiesinger via Postfix-users wrote: Hi everyone, I'm not sure if I'm missing something but I can't find out why my body_checks doesn't catch all the backscatter I'm getting right now. Oh yuck. I've found that the best way to block backscatter is by using

[pfx] Re: body_checks not catching all backscatter

On 27.04.23 17:59, Sebastian Wiesinger via Postfix-users wrote: I'm not sure if I'm missing something but I can't find out why my body_checks doesn't catch all the backscatter I'm getting right now. I've it configured like this: root@alita:/etc/postfix# postconf -n body_checks body_checks

[pfx] Re: body_checks not catching all backscatter

* Sebastian Wiesinger [2023-04-27 17:59]: > root@alita:/etc/postfix# postmap -q - regexp:/etc/postfix/body_checks.pcre > Message-ID: > reject SPAM backscatter with forged domain name in Message-ID header And of course I ran into my own filter when I got the mail

[pfx] body_checks not catching all backscatter

Hi everyone, I'm not sure if I'm missing something but I can't find out why my body_checks doesn't catch all the backscatter I'm getting right now. I've it configured like this: root@alita:/etc/postfix# postconf -n body_checks body_checks = pcre:$config_directory/body_checks.pcre root@alita

Re: Preventing .forward backscatter

On Mon, Jun 27, 2022 at 02:15:18PM -0700, Derek B. Noonburg wrote: > > If you can convince the user to surrender the alias management to you, > > then you instead configure: > > > > > > owner-user: user > > user: some.a...@gmail.com > > > > And presto magic, email to gmail will be

Re: Preventing .forward backscatter

gt;> has a .forward file that points to a gmail address. Gmail's servers >>> are rejecting some email for various causes ("low reputation of >>> sending domain", SPF failures). >>> >>> The problem is that postfix then bounces the email back to the >>&

Re: Preventing .forward backscatter

> > are rejecting some email for various causes ("low reputation of > > sending domain", SPF failures). > > > > The problem is that postfix then bounces the email back to the > > (likely forged) sender, which means my server is sending > > backscatter

Re: Preventing .forward backscatter

On 23.06.22 14:43, Derek B. Noonburg wrote: I'm running postfix to handle email for several users. One of them has a .forward file that points to a gmail address. Gmail's servers are rejecting some email for various causes ("low reputation of sending domain", SPF failures). one of tricks is

Re: Preventing .forward backscatter

On Fri, Jun 24, 2022 at 09:48:20AM -0400, Wietse Venema wrote: > > If you can convince the user to surrender the alias management to you, > > then you instead configure: > > > > owner-user: user > > user: some.a...@gmail.com > > > > And presto magic, email to gmail will be forwarded

Re: Preventing .forward backscatter

causes ("low reputation of > > sending domain", SPF failures). > > > > The problem is that postfix then bounces the email back to the (likely > > forged) sender, which means my server is sending backscatter. > > > > What I'd like to do is silent

Re: Preventing .forward backscatter

And that might occur for both validly spam messages as well as invalidly non-spam messages. > The problem is that postfix then bounces the email back to the (likely > forged) sender, which means my server is sending backscatter. In the case of validly rejected spam. > What I'd like to do is

Re: Preventing .forward backscatter

ding domain", SPF failures). > > The problem is that postfix then bounces the email back to the (likely > forged) sender, which means my server is sending backscatter. > > What I'd like to do is silently drop any email that's rejected by the > target of a .forward file.

Re: Preventing .forward backscatter

he problem is that postfix then bounces the email back to the (likely forged) sender, which means my server is sending backscatter. Does that then become forwardscatter? :) -- Phil Stracchino Babylon Communications ph...@caerllewys.net p...@co.ordinate.org Landline: +1.603.293.848

Preventing .forward backscatter

email back to the (likely forged) sender, which means my server is sending backscatter. What I'd like to do is silently drop any email that's rejected by the target of a .forward file. Is there some way to configure postfix to do that? Or some better way of handling this problem? Thanks in advance for

Re: Stopping backscatter spam to a specific domain

nt_restrictions (because I didn’t have that set) >> but because it had to in order to deliver local messages. When I switched >> to LMTP that was no longer the case. Postfix now thought it was possible >> to deliver to non-existent users, and that’s what result

Re: Stopping backscatter spam to a specific domain

, and that’s what resulted in the backscatter. it MAY still be possible to set up postfix to read local recipients from database dovecot uses. Look at local_recipient_maps directive if it's possible, depends on your dovecot setup. reject_unverified_recipient requires verifying each recipient and keep

Re: Stopping backscatter spam to a specific domain

at’s what resulted in the backscatter. Now I understand why the conventional wisdom is not to run your own email server :-) Thanks to all who responded! rg

Re: Stopping backscatter spam to a specific domain

On 11.07.21 23:26, Ron Garret wrote: This has me wondering: if a message is sent to multiple recipients and some are valid and others are not, what is the Right Thing to do? The right thing is to refuse all non-existing recipients, which postfix does by default if it knows what addresses

Re: Stopping backscatter spam to a specific domain

Thanks, that was very helpful. This has me wondering: if a message is sent to multiple recipients and some are valid and others are not, what is the Right Thing to do? rg P.S. Just FYI: > I'm not sure what the problem is with Postfix and sqlite See

Re: Stopping backscatter spam to a specific domain

On 7/11/21 3:46 PM, Ron Garret wrote: Ah. That may be my problem then. I’m using Dovecot via LMTP for local delivery. I thought that postfix would receive information about non-existent users via that protocol, but I guess it doesn’t and ends up just accepting everything. So… is dovecot

Re: Stopping backscatter spam to a specific domain

On 2021-07-11 at 15:46:45 UTC-0400 (Sun, 11 Jul 2021 12:46:45 -0700) Ron Garret is rumored to have said: On Jul 11, 2021, at 12:22 PM, Matus UHLAR - fantomas wrote: The problem is that a rejected recipient produces a mailer-daemon reply. only if you accept mail for such recipient.

Re: Stopping backscatter spam to a specific domain

Ron Garret: [ Charset windows-1252 converted... ] > > On Jul 11, 2021, at 12:22 PM, Matus UHLAR - fantomas > wrote: > > > > >> The problem is that a rejected recipient produces a mailer-daemon reply. > > > > only if you accept mail for such recipient. > > Ah. That may be my problem then.

Re: Stopping backscatter spam to a specific domain

Hi, I thought that postfix would receive information about non-existent users via that protocol, but I guess it doesn’t and ends up just accepting everything. These are two different things: 1. postfix gets the e-mail from the internet via smtp and puts in his queue. From this point on

Re: Stopping backscatter spam to a specific domain

On Jul 11, 2021, at 12:22 PM, Matus UHLAR - fantomas wrote: > >> The problem is that a rejected recipient produces a mailer-daemon reply. > > only if you accept mail for such recipient. Ah. That may be my problem then. I’m using Dovecot via LMTP for local delivery. I thought that

Re: Stopping backscatter spam to a specific domain

Ron Garret: I have recently come under a backscatter spam attack from one specific domain. This domain has blacklisted my server?s IP address, and so bounce replies sent to this domain are piling up in my mail queue and I have to go through periodically and manually delete them. I don?t want

Re: Stopping backscatter spam to a specific domain

Hi, The problem is that a rejected recipient produces a mailer-daemon reply. You need to get rid of them. My approach is to reject them in smtp dialogue. I generate a list of valid recipient addresses by script automatically and use this (hashed) list in smtpd_recipient_restrictions:

Re: Stopping backscatter spam to a specific domain

See http://www.postfix.org/DEBUG_README.html#mail, which describes how best to get useful help here. Actual log excerpts, sample messages related to that logging, and 'postconf -n' output would help a great deal in understanding your problem. In general, you only can fully fix backscatter

Re: Stopping backscatter spam to a specific domain

Yes, I looked at that, but AFAICT that is all about blocking INBOUND backscatter spam, not stopping outbound messages. On Jul 11, 2021, at 10:15 AM, Kevin N. wrote: > This might help: http://www.postfix.org/BACKSCATTER_README.html > > Cheers, > > K. > > >>

Re: Stopping backscatter spam to a specific domain

On Jul 11, 2021, at 10:12 AM, Wietse Venema wrote: > Ron Garret: > [ Charset windows-1252 converted... ] >> >> On Jul 11, 2021, at 9:58 AM, Wietse Venema wrote: >> >>> Ron Garret: >>>> I have recently come under a backscatter spam attack fr

Re: Stopping backscatter spam to a specific domain

This might help: http://www.postfix.org/BACKSCATTER_README.html Cheers, K. On Jul 11, 2021, at 9:58 AM, Wietse Venema wrote: Ron Garret: I have recently come under a backscatter spam attack from one specific domain. This domain has blacklisted my server?s IP address, and so bounce

Re: Stopping backscatter spam to a specific domain

Ron Garret: [ Charset windows-1252 converted... ] > > On Jul 11, 2021, at 9:58 AM, Wietse Venema wrote: > > > Ron Garret: > >> I have recently come under a backscatter spam attack from one > >> specific domain. This domain has blacklisted my server?s IP > &g

Re: Stopping backscatter spam to a specific domain

On Jul 11, 2021, at 9:58 AM, Wietse Venema wrote: > Ron Garret: >> I have recently come under a backscatter spam attack from one >> specific domain. This domain has blacklisted my server?s IP >> address, and so bounce replies sent to this domain are piling up >>

Re: Stopping backscatter spam to a specific domain

Ron Garret: > I have recently come under a backscatter spam attack from one > specific domain. This domain has blacklisted my server?s IP > address, and so bounce replies sent to this domain are piling up > in my mail queue and I have to go through periodically and manually > dele

Stopping backscatter spam to a specific domain

I have recently come under a backscatter spam attack from one specific domain. This domain has blacklisted my server’s IP address, and so bounce replies sent to this domain are piling up in my mail queue and I have to go through periodically and manually delete them. I don’t want to disable

Re: connect then disconnect; backscatter?

On 18.04.21 07:55, li...@lazygranch.com wrote: I need to learn postscreen eventually for other spammers. mostly bots, but thanks to dnsbl scoring, spammers too. The thing with fail2ban or the similar sshguard is I have a huge block list for the webserver. It has been my experience that these

Re: connect then disconnect; backscatter?

On Sun, 18 Apr 2021 21:29:26 +1200 Nick Tait wrote: > On 18/04/21 7:32 pm, li...@lazygranch.com wrote: > > And so it goes. I suppose if this really bugs me I can block the > > server in firewalld. I've yet to see it actually deliver mail. Or > > complain to the data center. > >

Re: connect then disconnect; backscatter?

On 18/04/21 7:32 pm, li...@lazygranch.com wrote: And so it goes. I suppose if this really bugs me I can block the server in firewalld. I've yet to see it actually deliver mail. Or complain to the data center. https://serveroffer.lt Firewalling is definitely the best solution to the problem

Re: connect then disconnect; backscatter?

On Sat, 17 Apr 2021 18:25:47 -0400 (EDT) Wietse Venema wrote: > li...@lazygranch.com: > > > You should enable SASL auth in master.cf NOT main.cf, and ONLY for > > > a service that needs SASL auth. > > > > > > Otherwise you're turning it on for the server-to-server port (25) > > > where it is

Re: connect then disconnect; backscatter?

On 2021-04-18 00:25, Wietse Venema wrote: Even with SASL turned off you will see that some bots try SASL auth. But with SASL turned they can't use this to verify passwords. http://www.postfix.org/SASL_README.html it could imho be dokumented not to make it global in this howto / manual

Re: connect then disconnect; backscatter?

li...@lazygranch.com: > > You should enable SASL auth in master.cf NOT main.cf, and ONLY for > > a service that needs SASL auth. > > > > Otherwise you're turning it on for the server-to-server port (25) > > where it is not doing any good. > > > > Wietse > > > > OK now it makes sense to

Re: connect then disconnect; backscatter?

On Sat, 17 Apr 2021 17:03:51 -0400 (EDT) Wietse Venema wrote: > li...@lazygranch.com: > > I do have "smtpd_sasl_auth_enable = yes" and I use port 587. Before > > I comment out that line, here is the general area of my main.cf > > dealing with sasl. I cut out my rbls but otherwise this is what

Re: connect then disconnect; backscatter?

li...@lazygranch.com: > I do have "smtpd_sasl_auth_enable = yes" and I use port 587. Before I > comment out that line, here is the general area of my main.cf dealing > with sasl. I cut out my rbls but otherwise this is what I use. Any other > problems? You should enable SASL auth in master.cf NOT

Re: connect then disconnect; backscatter?

On Sat, 17 Apr 2021 14:35:37 +0200 Benny Pedersen wrote: > On 2021-04-17 09:58, li...@lazygranch.com wrote: > > I am getting a lot of these: > > > > Apr 17 07:27:10 mydomain postfix/smtpd[21897]: connect from > > mone183.secundiarourous.com[141.98.10.183] > > Apr 17 07:27:11 mydomain

Re: connect then disconnect; backscatter?

Hello, On Sat, 17 Apr 2021, Francesc Peñalvez wrote: Is it possible to identify which password smtp is trying to use? if so I would like to know how With dovecot, you can set: auth_verbose = yes auth_verbose_passwords = plain When I'm bored, I run: #!/bin/sh grep "given password: "

Re: logging failed AUTH (was: connect then disconnect; backscatter?)

On Sat, Apr 17, 2021, Wietse Venema wrote: > Francesc Pe?alvez: > > Is it possible to identify which password smtp is trying to use? if so I > > would like to know how This seems to be a common request hence several people submitted patches for sendmail to identify at least the account:

Re: connect then disconnect; backscatter?

li...@lazygranch.com: > Apr 17 07:27:11 mydomain postfix/smtpd[21897]: disconnect from > mone183.secundiarourous.com[141.98.10.183] ehlo=1 auth=0/1 quit=1 commands=2/3 Wietse: > They send quit after sending EHLO and AUTH (which failed). I use > the regexp "auth=./" to identify password-guessing

Re: connect then disconnect; backscatter?

Is it possible to identify which password smtp is trying to use? if so I would like to know how El 17/04/2021 a las 14:13, Wietse Venema escribió: li...@lazygranch.com: I am getting a lot of these: Apr 17 07:27:10 mydomain postfix/smtpd[21897]: connect from

Re: connect then disconnect; backscatter?

On 2021-04-17 09:58, li...@lazygranch.com wrote: I am getting a lot of these: Apr 17 07:27:10 mydomain postfix/smtpd[21897]: connect from mone183.secundiarourous.com[141.98.10.183] Apr 17 07:27:11 mydomain postfix/smtpd[21897]: disconnect from mone183.secundiarourous.com[141.98.10.183] ehlo=1

Re: connect then disconnect; backscatter?

li...@lazygranch.com: > I am getting a lot of these: > > Apr 17 07:27:10 mydomain postfix/smtpd[21897]: connect from > mone183.secundiarourous.com[141.98.10.183] > Apr 17 07:27:11 mydomain postfix/smtpd[21897]: disconnect from > mone183.secundiarourous.com[141.98.10.183] ehlo=1 auth=0/1 quit=1

connect then disconnect; backscatter?

I am getting a lot of these: Apr 17 07:27:10 mydomain postfix/smtpd[21897]: connect from mone183.secundiarourous.com[141.98.10.183] Apr 17 07:27:11 mydomain postfix/smtpd[21897]: disconnect from mone183.secundiarourous.com[141.98.10.183] ehlo=1 auth=0/1 quit=1 commands=2/3 Googling

Re: Backscatter problems + fixes + RFC idea

On 20/03/2021 18:52, Rahul Dhesi wrote: On Sat, 20 Mar 2021, Dominic Raferd wrote: You may find my script helpful: https://www.timedicer.co.uk/programs/help/relay-enforcer.sh.php Looks very interesting, thanks. I ran 'shellcheck' on it and saw many scary warnings; highly recommended to

Re: Backscatter problems + fixes + RFC idea

On Sat, 20 Mar 2021, Dominic Raferd wrote: You may find my script helpful: https://www.timedicer.co.uk/programs/help/relay-enforcer.sh.php Looks very interesting, thanks. I ran 'shellcheck' on it and saw many scary warnings; highly recommended to revise the code to fix all of them. Rahul

Re: Backscatter problems + fixes + RFC idea

On 20/03/2021 01:53, Rahul Dhesi wrote: On Fri, 19 Mar 2021, Wietse Venema wrote: See examples in: http://www.postfix.org/postconf.5.html#default_delivery_status_filter (this was originally designed to turn soft TLS errors into hard ones). Thanks, that is a vey nice feature I did not know

Re: Backscatter problems + fixes + RFC idea

On Fri, 19 Mar 2021, Wietse Venema wrote: See examples in: http://www.postfix.org/postconf.5.html#default_delivery_status_filter (this was originally designed to turn soft TLS errors into hard ones). Thanks, that is a vey nice feature I did not know about. I should mention that my strategy

Re: Backscatter problems + fixes + RFC idea

Rahul Dhesi: > There is a second problem for which the fix is not so elegant. If Gmail > detects spam but returns a temporary error, the spam will remain in the > queue until its lifetime expires. The only way I found of dealing with > this is to run a cron job that does 'mailq', finds Gmail

Backscatter problems + fixes + RFC idea

A fix that I recently applied for a backscatter problem. Gmail is the example used below, but the problem and solution are not Gmail-specific. The problem: Spam arrives for a user, gets past spam filter, is forwarded by receiving user to their Gmail address, gets a permanent rejection from

Re: Postfix backscatter HELP !!!

Thanks guys in the mean time I found the way to do it by trial and error and works OK now On 2/2/21 8:12 PM, Viktor Dukhovni wrote: On Tue, Feb 02, 2021 at 12:27:40PM +0200, George Papas wrote: # Do not indent the patterns between "if" and "endif". if /^[> ]*Received:/ /^[> ]*Received: +from

Re: Postfix backscatter HELP !!!

On Tue, Feb 02, 2021 at 12:27:40PM +0200, George Papas wrote: > # Do not indent the patterns between "if" and "endif". > if /^[> ]*Received:/ > /^[> ]*Received: +from +ip53\.ip-139-99-176\.net / > reject forged sender name in Received: header: $1 > endif The above syntax is wrong. The "reject

Re: Postfix backscatter HELP !!!

counts but > > I cant find out how to stop bombing my server with backscatter mails > from all over . > > I tried to implement body_checks using the following : > > > my main.cf : > > header_checks = regexp:/etc/postfix/header_checks > body_checks = pcre:/etc/po

Postfix backscatter HELP !!!

with backscatter mails from all over . I tried to implement body_checks using the following : my main.cf : header_checks = regexp:/etc/postfix/header_checks body_checks = pcre:/etc/postfix/body_checks body_checks : # Do not indent the patterns between "if" and "endif"

Re: Avoiding sending backscatter

stent email, it > > accepts it anyways because it doesn't have the list of valid email > > addresses> In other words, I'm generating backscatter and I want to avoid > > it. > > > >One solution could be to never return a mail delivery notification for > > exter

Re: Avoiding sending backscatter

email addresses> >In other words, I'm generating backscatter and I want to avoid it. > >One solution could be to never return a mail delivery notification for > external email, but I think that's not recommended, isn't it? Right, that's a terrible idea that breaks the reliability

Avoiding sending backscatter

Hello everyone, I have a postfix server (with amavis and clamav) that receives emails for other domains. When it gets a mail for a non-existent email, it accepts it anyways because it doesn't have the list of valid email addresses. In other words, I'm generating backscatter and I want

Re: Problem with virtual_alias_maps and backscatter

Hi, Am 20.05.2018 um 16:40 schrieb Wietse Venema: [...] > Indeed. With Postfix 2.4 and later, both the virtual(5) and > canonical(5) manpages document that wildcard address mappings will > break adress validation. > Yes i read that but as said was surprised that this included lookups to the very

Re: Problem with virtual_alias_maps and backscatter

equinox: > Re-reading the documentation over and over again i yesterday realized > that a simple non-regexp table containing > > > @example.com@example.org > ... > > > does suffice to do the same thing. However the problem i'm having stays > the same. Indeed. With Postfix 2.4 and later,

Problem with virtual_alias_maps and backscatter

this: /^(.*)@example\.com$/${1}@example.org /^foo@example\.org$/ f...@some-other-domain.org /^bar@example\.org$/ bar@external-domain.something This worked just fine but, for some reason only now, i realized this makes @example.com a backscatter spam source. Re-reading the documentation over and over

Re: Eliminating backscatter

thing goes wrong you will see it, but no backscatter is going out. In case of valid bounces (never really happens here) you need to inform the sender manually. Note that myuser should not be used otherwise or you will also get any other bounces, not only the forwards. There is pro

Re: Eliminating backscatter

. And this is exactly what causes backscatter. Don't accept mail to non-existent recipients. If you really must accept it (why?), don't forward it, especially not to gmail. -- Matus UHLAR - fantomas, uh...@fantomas.sk ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising

Re: Eliminating backscatter

Hi Noel, >> On Oct 30, 2017, at 6:42 PM, Noel Jones <njo...@megan.vbhcs.org> wrote: >> >> On 10/30/2017 5:07 PM, J Doe wrote: >> >> How do I stop backscatter generated from my server in response to the >> bounces from Gmail ? > > This is

Re: Eliminating backscatter

On 10/30/2017 5:07 PM, J Doe wrote: > > How do I stop backscatter generated from my server in response to the bounces > from Gmail ? > This is a very difficult problem to solve. Your choices are a) don't accept spam, or b) don't forward to gmail. There may be information on t

Re: Eliminating backscatter

a non-delivery e-mail to >> the origin address of the spam. Of course, as some of those addresses are >> forged, my server is producing backscatter. > > > Your mail server must have a list of valid recipients and reject > mail to unknown recipients. Where to list the

Re: Eliminating backscatter

n addresses sometimes > comes into my server that is addressed to virtual domain addresses. My > server rejects some of this spam and then generates a non-delivery e-mail to > the origin address of the spam. Of course, as some of those addresses are > forged, my server is producing bac

Eliminating backscatter

domain addresses. My server rejects some of this spam and then generates a non-delivery e-mail to the origin address of the spam. Of course, as some of those addresses are forged, my server is producing backscatter. I read the “Backscatter Howto” [1] on the Postfix website, but from what I read

Re: Backscatter questions

On 01 Oct 2017, at 09:59, Matus UHLAR - fantomas wrote: > a little searching says it's correct: > > https://www.mail-archive.com/postfix-users@postfix.org/msg25973.html Excellent! Thanks for researching that. -- Apple broke AppleScripting signatures in Mail.app, so no

Re: Backscatter questions

On 01 Oct 2017, at 08:50, Matus UHLAR - fantomas wrote: 2. their sender addresses should be validated with smtpd_reject_unlisted_sender On 01.10.17 09:22, @lbutlr wrote: Do Address delimiters have an issue with this? I thought they did. I thought that's exactly what

Re: Backscatter questions

On 01 Oct 2017, at 08:50, Matus UHLAR - fantomas wrote: > 2. their sender addresses should be validated with > smtpd_reject_unlisted_sender Do Address delimiters have an issue with this? I thought they did. That is, u...@example.com sends and email "from"

Re: Backscatter questions

On 27.09.17 13:49, J Doe wrote: 1. From what I understand, “backscatter” refers to e-mails such as non-delivery reports being sent back to the originator of a spam message. As the originator is often a forged address, the non-delivery reports is essentially junk data. Would this be a correct

Re: Backscatter questions

serious ?, then setyp postfix client sasl auth to gmail pr user > > > > if not want all that problems drop forwards > > Hi, > > Thanks for your reply Benny. Does anyone else have any advice > regarding backscatter on a virtual domain Postfix setup ? Yes. Just do not forward spam. Wietse

Re: Backscatter questions

problems drop forwards Hi, Thanks for your reply Benny. Does anyone else have any advice regarding backscatter on a virtual domain Postfix setup ? Thanks, - J

Re: Backscatter questions

J Doe skrev den 2017-09-27 22:20: [snip] Is there a way to achieve this or as you noted, are whitelists to be avoided ? If whitelists are to be avoided what is the best practice for handling this scenario ? why not add example.org on google apps mx ? :=) if useers not wanting your

Re: Backscatter questions

> On Sep 27, 2017, at 2:08 PM, Benny Pedersen <m...@junc.eu> wrote: > > J Doe skrev den 2017-09-27 19:49: > >> I recently configured Postfix 3.1.0 on a low-volume, Internet facing >> server. Mail operations are normal, but I had two questions regarding >>

Re: Backscatter questions

J Doe skrev den 2017-09-27 19:49: I recently configured Postfix 3.1.0 on a low-volume, Internet facing server. Mail operations are normal, but I had two questions regarding backscatter. ... 1. From what I understand, “backscatter” refers to e-mails such as non-delivery reports being sent

Backscatter questions

Hello, I recently configured Postfix 3.1.0 on a low-volume, Internet facing server. Mail operations are normal, but I had two questions regarding backscatter. 1. From what I understand, “backscatter” refers to e-mails such as non-delivery reports being sent back to the originator of a spam

Re: Prevent Backscatter

feed him for a lifetime. -- View this message in context: http://postfix.1071664.n5.nabble.com/Prevent-Backscatter-tp88359p88413.html Sent from the Postfix Users mailing list archive at Nabble.com.

Re: Prevent Backscatter

Postfix User: > Postfix User wrote > > I am trying to reject instead of sending bounce message back when email > > arrives to non existing account at domains hosted by my server. > > Anyone having similar problem, check_recipient_access map fixed my problem That is bad advice that covers up a

Re: Prevent Backscatter

name='%u' AND u.domain='%d' AND u.active='1'; -- View this message in context: http://postfix.1071664.n5.nabble.com/Prevent-Backscatter-tp88359p88404.html Sent from the Postfix Users mailing list archive at Nabble.com.

Re: Prevent Backscatter

omains.cf virtual_alias_domains.cf query = SELECT u.domain FROM users u WHERE u.username='%u' AND u.domain='%d' AND u.active='1'; -- View this message in context: http://postfix.1071664.n5.nabble.com/Prevent-Backscatter-tp88359p88391.html Sent from the Postfix Users mailing lis

Re: Prevent Backscatter

ame with the from address ) Fromremote address To local address Action OK Not authenticated sender Fromany To local address Action OK Fromremote address To remote address Action REJECT -

Re: Prevent Backscatter

Wietse Venema: > Postfix User: > > smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, > > reject_unauth_destination > > This will be an open relay if all your SMTP mail is logged with the > same client IP address, i.e. your SMTP mail comes from some box > that is in

Re: Prevent Backscatter

only trusted people that have direct access to the server or authenticated webmail users can send from localhost -- View this message in context: http://postfix.1071664.n5.nabble.com/Prevent-Backscatter-tp88359p88388.html Sent from the Postfix Users mailing list archive at Nabble.com.

Re: Prevent Backscatter

Postfix User: > smtpd_relay_restrictions = permit_mynetworks, permit_sasl_authenticated, > reject_unauth_destination This will be an open relay if all your SMTP mail is logged with the same client IP address, i.e. your SMTP mail comes from some box that is in mynetworks, and Postfix never sees

Re: Prevent Backscatter

ly, and I set relay_domains to empty. At the moment all works like expected, except the backscatter problem. This is latest postconf append_dot_mydomain = no biff = no broken_sasl_auth_clients = yes config_directory = /etc/postfix dovecot_destination_recipient_limit = 1 inet_interface

Re: Prevent Backscatter

You are right, there are no recipient restrictions, except permit_sasl_authenticated restricting remote recipients for authenticated clients only. -- View this message in context: http://postfix.1071664.n5.nabble.com/Prevent-Backscatter-tp88359p88385.html Sent from the Postfix Users mailing

Re: Prevent Backscatter

herefore, "check_sender_access $virtual_alias_maps" is rather > wrong. > > -- > Viktor. -- View this message in context: http://postfix.1071664.n5.nabble.com/Prevent-Backscatter-tp88359p88384.html Sent from the Postfix Users mailing list archive at Nabble.com.

  1   2   3   4   5   >