The Wiert Corner – irregular stream of stuff

Jeroen W. Pluimers on .NET, C#, Delphi, databases, and personal interests

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Archive for the ‘Communications Development’ Category

Some links on Chrome not prompting to save passwords (when Firefox and Safari do)

Posted by jpluimers on 2022/01/20

For quite some time now, Chrome (think years) refuses to prompt for saving passwords whereas Firefox and Safari do prompt and save them, even for site types that it used to save passwords for in the past.

It has been annoying enough for too long now that I tried to do better than the Google searches I used back when I saw this happen first.

Below are some links based on new searches (starting with [Wayback] adding a password in chrome settings – Google Search); hopefully I can try them after I made a list of sites that Chrome does not show the password save prompt for.

Solutions I tried that failed (but maybe useful for others):

Solutions still to try:

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Posted in Chrome, Chrome, Communications Development, Development, Encryption, ESXi6, ESXi6.5, ESXi6.7, Firefox, Fritz!, Fritz!Box, Fritz!WLAN, Google, https, HTTPS/TLS security, Internet, Internet protocol suite, Let's Encrypt (letsencrypt/certbot), Power User, routers, Safari, Security, TCP, TLS, Virtualization, VMware, VMware ESXi, Web Browsers, Web Development | Leave a Comment »

Which SMTP Port Should I Use? Learn Ports 25, 465, & 587 (and unofficial port 2525) | Mailgun

Posted by jpluimers on 2021/11/30

When trying to deliver mail, it is important to know which protocols and ports you can use.

On smtp, smtp-submission, smtps (ports 25, 587 and 465) and unofficial port 2525 (which Maingun maps to `smtp-submission): [Wayback] Which SMTP Port Should I Use? Learn Ports 25, 465, & 587 | Mailgun

Quote on why smtps port 465 is hardly used:

Port 465:

IANA has reassigned a new service to this port, and it should no longer be used for SMTP communications.

However, because it was once recognized by IANA as valid, there may be legacy systems that are only capable of using this connection method. Typically, you will use this port only if your application demands it. A quick Google search, and you’ll find many consumer Inbox Service Providers’ (ISPs) articles that suggest port 465 as the recommended setup. However, we do not recommend it, as it is not RFC compliant.


Posted in Communications Development, Development, Internet protocol suite, SMTP, Software Development, TLS, Web Development | Leave a Comment »

GitHub – TimeToogo/tunshell: Remote shell into ephemeral environments 🐚 🦀

Posted by jpluimers on 2021/11/25

Cool: [Wayback/] GitHub – TimeToogo/tunshell: Remote shell into ephemeral environments 🐚 🦀

Via: [] Jan Schaumann on Twitter: “This looks neat: on-demand remote shell into ephemeral environments, e.g. CI/CD pipeline container. Both sides fetch a client, use rendezvous server to negotiate session info, then establish connection or fall back to proxy through rendezvous. “

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Posted in Communications Development, Development, DevOps, HTTP, Infrastructure, Internet protocol suite, Power User, Software Development, TCP, WebSockets | Leave a Comment »

Some scripts and tips for easing the maintenance of a postfix based SMTP system

Posted by jpluimers on 2021/11/24

A few scripts and tips I found Googling around.

Deleting queued messages by regular expression pattern

I have seen the below script numerous time, usually without any attribution (for instance [Wayback] Postfix Flush the Mail Queue – nixCraft and  [Wayback] – Following script deletes all mail from the mailq which matches the regular expression specified as the first argument · GitHub).

The earliest version I could find was in [Wayback] ‘Re: delete messages from mailq’ – MARC by [Wayback] ‘Ralf Hildebrandt ‘ posts – MARC:

--- snip ---

$REGEXP = shift || die "no email-adress given (regexp-style, e.g. bl.*\!";

@data = qx</usr/sbin/postqueue -p>;
for (@data) {
  if (/^(\w+)\*?\s/) {
     $queue_id = $1;
  if($queue_id) {
    if (/$REGEXP/i) {
      $Q{$queue_id} = 1;
      $queue_id = "";
#open(POSTSUPER,"|cat") || die "couldn't open postsuper" ;
open(POSTSUPER,"|postsuper -d -") || die "couldn't open postsuper" ;

foreach (keys %Q) {
  print POSTSUPER "$_\n";
--- snip ---

And then use:
% delete-from-mailq "^test"



[Wayback] How do I check the postfix queue size? – Server Fault

Lots of great answers and pointers to useful guides/software there.


[Wayback] Postfix Bottleneck Analysis points to [Wayback] Postfix manual – qshape(1): qshape - Print Postfix queue domain and age distribution, then explains about different scenarion and queues:


postqueue -p | tail -n 1

Last line in the postqueue -p shows how many requests and size:

-- 317788 Kbytes in 11860 Requests.

View queues size

I tried finding the original posting of the below script, but could not. If you find it, please let me know.

#!/usr/bin/env perl

# postfix queue/s size
# author: 
# source:

use strict;
use warnings;
use Symbol;
sub count {
        my ($dir) = @_;
        my $dh = gensym();
        my $c = 0;
        opendir($dh, $dir) or die "$0: opendir: $dir: $!\n";
        while (my $f = readdir($dh)) {
                if ($f =~ m{^[A-F0-9]{5,}$}) {
                } elsif ($f =~ m{^[A-F0-9]$}) {
                        $c += count("$dir/$f");
        closedir($dh) or die "closedir: $dir: $!\n";
        return $c;
my $qdir = `postconf -h queue_directory`;
chdir($qdir) or die "$0: chdir: $qdir: $!\n";
printf "Incoming: %d\n", count("incoming");
printf "Active: %d\n", count("active");
printf "Deferred: %d\n", count("deferred");
printf "Bounced: %d\n", count("bounce");
printf "Hold: %d\n", count("hold");
printf "Corrupt: %d\n", count("corrupt");

Various commands

[Wayback] Inspecting Postfix’s email queue – Tech-G explaining about:

  • mailq
  • postqueue -p
  • postcat -vq XXXXXXXXXX (where XXXXXXXXXX is the message ID)
  • postqueue -f / postfix flush
  • postsuper -d to delete messages

More of these in [Wayback] Postfix Mail Queue Management – Linux Hint and [Wayback] Postfix Bottleneck Analysis: queues.


Based on [Wayback] Using “make” for Postfix file maintenance

MAPS = relays.db aliases.db transport.db relocated.db \
        virtual.db sender_checks.db rejected_recips.db \

all : $(MAPS)

aliases.db : aliases

%.db : %
        postmap $*

This is my Makefile that runs fine on Tumbleweed (note: all 8-space indents are TAB characters):

MAPS =  /etc/aliases.db \
        transport.db \
        virtual.db \
        helo_access.db \
        canonical.db \
        sasl_passwd.db \
        relocated.db \
        relay.db \
        access.db \
        relay_ccerts.db \

all : $(MAPS)

aliases.db : aliases
        @echo "Rebuilding $@."

%.db : %
        @echo "Rebuilding $@."
        postmap $*

In the future, I might try [Wayback] Makefile.postfix · GitHub, though I think it is convoluted:

## Postfix: Makefile to update *.db files
POSTCONF= /usr/sbin/postconf
POSTMAP= /usr/sbin/postmap
default: postmap
postmap: Makefile.postmap
@echo 'Updating database files …'
$(MAKE) -f Makefile.postmap
@echo 'Updating $@ …'
@set -e; \
rm -f $@.$$$$.tmp; \
echo 'POSTMAP=$(POSTMAP)' >>$@.$$$$.tmp; \
echo 'postmap::' >>$@.$$$$.tmp; \
config_directory="$(PWD)"; \
{ $(POSTCONF) -c $(PWD) || kill $$$$; } \
|tr ' ' '\n' \
|sed -n \
-e 's/,$$//' \
-e 's#^hash:\$$config_directory/##p' \
-e 's#^hash:'"$$config_directory/##p" \
|sort -u \
|while read mapfile; do \
echo "postmap:: $$mapfile.db" >>$@.$$$$.tmp; \
echo "$$mapfile.db: $$mapfile" >>$@.$$$$.tmp; \
echo " \$$(POSTMAP) $$<" >>$@.$$$$.tmp; \
done; \
mv $@.$$$$.tmp $@



[Wayback] Ralf Hildebrandt

Ralf Hildebrandt is an active and well-known figure in the Postfix community. He’s a systems engineer for T-NetPro, a German telecommunications company and has spoken about Postfix at industry conferences and contributes regularly to a number of open source mailing lists.

Co-author of this book: [Wayback: Book of Postfix State-of-the-Art Message Transport ISBN 9781593270018] (which used to have its own site: [Wayback: The Book of Postfix]

Book of Postfix

State-of-the-Art Message Transport

By Patrick KoetterRalf Hildebrandt

Publisher: No Starch PressRelease Date: March 2005Pages: 496

Best practices for Postfix–the popular alternative to Sendmail. Developed with security and speed in mind, Postfix has become a popular alternative to Sendmail and comes preinstalled in many Linux distributions as the default mailer. The Book of Postfix is a complete guide to Postfix whether used at home, as a mailrelay or virus-scanning gateway, or as a company mailserver. Practical examples show how to deal with daily challenges like protecting mail users from spam and viruses, managing multiple domains, and offering roaming access.

This is a great review of the book: [Wayback] The Book of Postfix (Ralf Hildebrandt, Patrick Koetter)


For my postfix studies… « The Wiert Corner – irregular stream of stuff



Posted in *nix, *nix-tools, bash, Communications Development, Development, Internet protocol suite, Makefile, postfix, Power User, Scripting, SMTP, Software Development | Leave a Comment »

Random User Generator | Home

Posted by jpluimers on 2021/11/23

Cool tool for when you ever need random users to test a system [Wayback] Random User Generator | Home:

Random user generator is a FREE API for generating placeholder user information. Get profile photos, names, and more. It’s like Lorem Ipsum, for people.

This was used when extracting Parler data to substantiate evidence around the 20210106 USA Capitol riots.

You can even use a simple HTTP GET like [Wayback] and get a JSON result like this.

{"results":[{"gender":"female","name":{"title":"Miss","first":"Malou","last":"Mortensen"},"location":{"street":{"number":2669,"name":"Lyngbyvej"},"city":"Sundby","state":"Syddanmark","country":"Denmark","postcode":48047,"coordinates":{"latitude":"-35.1307","longitude":"113.7480"},"timezone":{"offset":"+1:00","description":"Brussels, Copenhagen, Madrid, Paris"}},"email":"","login":{"uuid":"981747de-66fe-40b0-87ea-adfe403fe1be","username":"purpleostrich871","password":"sweets","salt":"x86aQbIB","md5":"55497ac53530b428f98b9d36267ceeef","sha1":"358b94ffabe7d827c34da15791e5d6717c594428","sha256":"6e357e887877e29b7e6d53073f648174382c53c24f83479e25fed9c82075ed32"},"dob":{"date":"1995-06-05T04:50:35.145Z","age":26},"registered":{"date":"2018-07-21T00:59:50.523Z","age":3},"phone":"02990797","cell":"94800012","id":{"name":"CPR","value":"050695-9954"},"picture":{"large":"","medium":"","thumbnail":""},"nat":"DK"}],"info":{"seed":"8971869bb62b73d7","results":1,"page":1,"version":"1.3"}}



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Posted in Communications Development, Development, HTTP, Internet protocol suite, JavaScript/ECMAScript, JSON, Python, REST, Scripting, Software Development, TCP | Leave a Comment »

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