Re: not working smtpd_recipient_restrictions implementation - postFIXED!
Thank you to all who answered. I learnt from each of the three emails. My config file was seriously wonky (I have become a spam reader -- oh and aparrently spam sender) so it took some persuading but at least for now this particular dragon is slain. Wietse, you belong on Mount Olympus. Best wishes and thanks to all Eric Wietse Venema previously_wrote on Wed-02-Jun 21 7:34PM > Eric Smith: > > Dear fixers, > > > > My postfix ability has dissapated over many years without use :-( > > > > I tried and failing to REJECT an unwanted domain from accessing postfix > > through this in main.cf > > > > smtpd_recipient_restrictions = permit_mynetworks, > > Postfix won't reject mail from your network. > > > permit_sasl_authenticated, > > Postfix won't reject mail from an authenticated client. > > > check_sender_access > > hash:/etc/postfix/sender_access, > > This applies only if the client did not match permit_mynetworks > and did not match permit_sasl_authenticated. > > Wietse > > > reject_unauth_destination, > > reject_rbl_client zen.spamhaus.org, > > reject_rhsbl_reverse_client dbl.spamhaus.org, > > ... > > > > > > /etc/postfix/sender_access > > example2.org REJECT > > unwelcome.tld REJECT > > END > > > > % postmap /etc/postfix/sender_access > > > > % ls /etc/postfix/sender_access* > > sender_access sender_access.db > > > > % sudo postfix restart > > > > > > I wonder if there are any clues here to what I am doing wrong or where I > > might try to fix this. > > > > Thank you in advance and best wishes > > Eric > >
Re: postfix.org site CSS change
Hi Daniel, On Wed, Jun 2, 2021 at 9:45 PM Daniel Ryšlink wrote: > Dear esteemed Postfix users and experts! > > First, let me apologize for intruding and discussing a Postfix unrelated > topic, but as a person whose health was affected by poor quality LCD (and > other) screens, I feel compelled to step forward and and provide a few > short pointers that could solve or at least mitigate Mr. Vybíhal's problems. > Thanks for the input, but I am not the OP :) Josef
Re: postfix.org site CSS change
Dear esteemed Postfix users and experts!
First, let me apologize for intruding and discussing a Postfix unrelated
topic, but as a person whose health was affected by poor quality LCD
(and other) screens, I feel compelled to step forward and and provide a
few short pointers that could solve or at least mitigate Mr. Vybíhal's
problems.
First of all, here is how to change color scheme to inverted ("Dark") in
the popular browser Chrome (other browsers will have similar options,
but you will have to research them yourself):
Either install Chrome Extenstion called "Dark Reader", or simply open
this URL:
chrome://flags
, search all the settings (flags) for the word "Dark", and switch the
option called "Force Dark Mode for Web Contents" to "Enabled", or
experiment with the other options and see what fits your needs the most.
Note that modern Android devices (from Android 10 up) support switching
to system-wide Dark color schemes, because bright windows and GUI
elements cause burn-in on modern OLED screens, so you can take advantage
of that.
That being said, the most problems "hurting your eyes" come not from the
bright colors themselves (although choosing dark color scheme mitigates
the problem), but from the phenomenon called "screen flicker". Most LCD
and all OLED screens use a technique called PWM (Pulse Width Modulation)
to control brightness, because they capable of only two states - off
(black) and on on maximum brightness. PWM periodically switches on and
off the screen, creating the illusion of dimming the screen gradually
(although it, in fact, does not) - there is a set PWM frequency,
starting from 240Hz (very bad, severe flicker) to thousands of kHz that
should theoretically be harmless, except it often is not, and according
to your brightness setting, the screen is dark part of the cycle and lit
during the rest (for example if brightness is set to 50%, it's exactly
half and half. if set to 100 percent, the scree usually does not flicker
at all, staying on all the time).
The sensitivity to screen flicker caused by PWM is very individual -
some (lucky) people do not register anything, some (like me), have
swollen, red eyes, headaches and pain in the eyes. There is a reaeach
proving that similar to flickering light used by EEG, PWM flicker
affects human neural system directly, and may cause yet unknown health
complication (at the very least, it tires us faster).
Today, the problem is well known and documented, so you can choose a
monitor (or laptop) whose screen is certified "flicker-free", which
means it does not use PWM, but direct current to control brightness
(being and incandescent light source, at the expense of slightly worse
color reproduction and accuracy). Good review sites (Prad, FlatpanelsHD,
rtings, tftcentral and others) use oscilloscope to measure the PWM
frequency and comment on its type and severity (or absence if it's the
case).
For more information, please google PWM, there is ample reading in both
English and Czech.
Lastly, I apologize to everyone for this rather verbose contribution, I
will shut myself up again immediately and switch back to lurking. Please
don't ban me from the list for this, your expertise and diligence solved
me many problems as Postfix server administrator, I very much value your
knowledge and strongly wish to be able to read your contributions.
Best regards to everyone, and thank you!
-- Daniel Ryšlink
On 02-Jun-21 20:08, Charles Sprickman wrote:
On Jun 2, 2021, at 1:40 PM, post...@ptld.com wrote:
On 06-02-2021 1:35 pm, Josef Vybíhal wrote:
the background was changed to white.
curl -sI http://www.postfix.org/postfix.css | grep Last
Last-Modified: Sun, 20 Feb 2011 12:14:00 GMT
Any ideas why the background "to me" is now white when its been yellow for
years?
I tried in both ff/edge browsers to make sure one browser wasn't acting strange.
What color is the background to you?
The CSS doesn’t declare any background color, so it’s fully up to the browser
(or any local stylesheet overrides) to alter the color.
Can’t recall ever seeing it as anything but white before...
Re: postfix.org site CSS change
> Any ideas why the background "to me" is now white when its been yellow for > years? There's a smoker in the house and you recently changed screens? -- Sam (cigars) On 2 June 2021 19:40:31 CEST, post...@ptld.com wrote: >> On 06-02-2021 1:35 pm, Josef Vybíhal wrote: >> >>> the background was changed to white. >> >> curl -sI http://www.postfix.org/postfix.css | grep Last >> Last-Modified: Sun, 20 Feb 2011 12:14:00 GMT > >Any ideas why the background "to me" is now white when its been yellow >for years? >I tried in both ff/edge browsers to make sure one browser wasn't acting > >strange. >What color is the background to you?
Re: postfix.org site CSS change
> On Jun 2, 2021, at 1:40 PM, post...@ptld.com wrote: > >> On 06-02-2021 1:35 pm, Josef Vybíhal wrote: >>> the background was changed to white. >> curl -sI http://www.postfix.org/postfix.css | grep Last >> Last-Modified: Sun, 20 Feb 2011 12:14:00 GMT > > Any ideas why the background "to me" is now white when its been yellow for > years? > I tried in both ff/edge browsers to make sure one browser wasn't acting > strange. > What color is the background to you? The CSS doesn’t declare any background color, so it’s fully up to the browser (or any local stylesheet overrides) to alter the color. Can’t recall ever seeing it as anything but white before...
Re: not working smtpd_recipient_restrictions implementation
On Wed, Jun 02, 2021 at 06:55:26PM +0200, Eric Smith wrote: > My postfix ability has dissapated over many years without use :-( > > I tried and failing to REJECT an unwanted domain from accessing postfix > through this in main.cf > > smtpd_recipient_restrictions = > permit_mynetworks, > permit_sasl_authenticated, > check_sender_access hash:/etc/postfix/sender_access, > reject_unauth_destination, It is best to list "check_sender_access ..." *after* "reject_unauth_destination": reject_unauth_destination, check_sender_access hash:/etc/postfix/sender_access, otherwise you risk open-relay accidents. Basically put "reject_unauth_destination" as early as possible in the restriction list. You may be protected by "smtpd_relay_restrictions", but if that's explicitly set empty, "smtpd_recipient_restrictions" is your last line of defense. -- Viktor.
Re: postfix.org site CSS change
On 06-02-2021 1:35 pm, Josef Vybíhal wrote: the background was changed to white. curl -sI http://www.postfix.org/postfix.css | grep Last Last-Modified: Sun, 20 Feb 2011 12:14:00 GMT Any ideas why the background "to me" is now white when its been yellow for years? I tried in both ff/edge browsers to make sure one browser wasn't acting strange. What color is the background to you?
Re: postfix.org site CSS change
On Wed, Jun 2, 2021 at 7:22 PM wrote: > To whomever is in charge of the postfix.org site; > > Just feedback, i noticed the site has been updated and the background > was changed to white. I personally preferred the darker non-white > background because it wasn't as bright/hard on the eyes. Not saying > yellow was my favorite color but it made it easier on the eyes. > > Thanks :) > curl -sI http://www.postfix.org/postfix.css | grep Last Last-Modified: Sun, 20 Feb 2011 12:14:00 GMT
Re: not working smtpd_recipient_restrictions implementation
Eric Smith: > Dear fixers, > > My postfix ability has dissapated over many years without use :-( > > I tried and failing to REJECT an unwanted domain from accessing postfix > through this in main.cf > > smtpd_recipient_restrictions = permit_mynetworks, Postfix won't reject mail from your network. > permit_sasl_authenticated, Postfix won't reject mail from an authenticated client. > check_sender_access > hash:/etc/postfix/sender_access, This applies only if the client did not match permit_mynetworks and did not match permit_sasl_authenticated. Wietse > reject_unauth_destination, > reject_rbl_client zen.spamhaus.org, > reject_rhsbl_reverse_client dbl.spamhaus.org, > ... > > > /etc/postfix/sender_access > example2.org REJECT > unwelcome.tld REJECT > END > > % postmap /etc/postfix/sender_access > > % ls /etc/postfix/sender_access* > sender_access sender_access.db > > % sudo postfix restart > > > I wonder if there are any clues here to what I am doing wrong or where I > might try to fix this. > > Thank you in advance and best wishes > Eric >
Re: postfix.org site CSS change
post...@ptld.com: > To whomever is in charge of the postfix.org site; > > Just feedback, i noticed the site has been updated and the background > was changed to white. I personally preferred the darker non-white > background because it wasn't as bright/hard on the eyes. Not saying > yellow was my favorite color but it made it easier on the eyes. The CSS has not changed. Wietse > Thanks :) >
postfix.org site CSS change
To whomever is in charge of the postfix.org site; Just feedback, i noticed the site has been updated and the background was changed to white. I personally preferred the darker non-white background because it wasn't as bright/hard on the eyes. Not saying yellow was my favorite color but it made it easier on the eyes. Thanks :)
Re: not working smtpd_recipient_restrictions implementation
On 06-02-2021 12:55 pm, Eric Smith wrote: Dear fixers, My postfix ability has dissapated over many years without use :-( I tried and failing to REJECT an unwanted domain from accessing postfix through this in main.cf Does anything show in the mail logs when it receives an email from the blocked domain that could give a clue? Any warnings on trying to access the sender access map? It is also possible to turn on full debugging in the logs which will explain postfix decision process when deciding to accept or reject an email. It shows step by step each matching attempt between the address and the records in the maps. http://www.postfix.org/DEBUG_README.html
not working smtpd_recipient_restrictions implementation
Dear fixers, My postfix ability has dissapated over many years without use :-( I tried and failing to REJECT an unwanted domain from accessing postfix through this in main.cf smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, check_sender_access hash:/etc/postfix/sender_access, reject_unauth_destination, reject_rbl_client zen.spamhaus.org, reject_rhsbl_reverse_client dbl.spamhaus.org, ... /etc/postfix/sender_access example2.org REJECT unwelcome.tld REJECT END % postmap /etc/postfix/sender_access % ls /etc/postfix/sender_access* sender_access sender_access.db % sudo postfix restart I wonder if there are any clues here to what I am doing wrong or where I might try to fix this. Thank you in advance and best wishes Eric
