The plan was to run a Postfix secondary MX inside a docker container.
Below are many links that might help me to get that going.
For now, I think this is the shortlist of solutions to try:
- Docker Mailserver
- Mailcow
- Mailu
Archive for the ‘*nix’ Category
Some notes on running Postfix inside a docker container
Posted by jpluimers on 2025/11/14
Posted in *nix, *nix-tools, Cloud, Communications Development, Containers, Development, Docker, Infrastructure, Internet protocol suite, Kubernetes (k8n), postfix, Power User, SMTP | Tagged: 254, 29, 52, 787, DMARC, domains, set | Leave a Comment »
roehling/postsrsd: Postfix Sender Rewriting Scheme daemon
Posted by jpluimers on 2025/11/12
This finally made me perform the (long overdue) migration from Sendmail to Postfix:
The Sender Rewriting Scheme (SRS) is a technique to forward mails from domains which deploy the Sender Policy Framework (SPF) to prohibit other Mail Transfer Agents (MTAs) from sending mails on their behalf. With SRS, an MTA can circumvent SPF restrictions by replacing the envelope sender with a temporary email address from one of their own domains. This temporary address is bound to the original sender and only valid for a certain amount of time, which prevents abuse by spammers.
[Wayback/Archive] roehling/postsrsd: Postfix Sender Rewriting Scheme daemon
Via a long queste to figure out why Gmail every now and then bounces forwarded messages because of Sender Policy Framework (SPF). Below are a few of the links that brought me here in mostly reverse order, but first some links that should help me further on the topic of Postfix virtual aliases.
The sendmail setup had some features not covered below (like a catch-all forward for email to addresses virtual domains not covered by a virtual alias) which I hopefully can cover later.
One thing learned both over the past decades and related postfix material: use separate servers or containers for each of your functions. So do not mix web-hosting, outgoing mail, incoming mail, fail2ban and others on the same server.
Links:
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Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, postfix, Power User, sendmail, SMTP | Tagged: Reload | Leave a Comment »
LinuxCND: The Raspberry Pi that ships other Raspberry Pis – Pi Australia
Posted by jpluimers on 2025/11/11
Cool practical application of LinuxCNC: [Wayback/Archive] The Raspberry Pi that ships other Raspberry Pis – Pi Australia
LinuxCNC controls CNC machines. It can drive milling machines, lathes, 3D printers, laser cutters, plasma cutters, robot arms, hexapods, and more.
Via [Wayback/Archive] Frans van Berckel on Twitter: “@geerlingguy So, there is a Raspberry Pi, that ships other Raspberry Pis?”
–jeroen
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Posted in *nix, *nix-tools, Development, Hardware Development, Linux, Power User, Raspberry Pi | Leave a Comment »
GitHub – louislam/uptime-kuma: A fancy self-hosted monitoring tool
Posted by jpluimers on 2025/11/05
As promised yesterday¹ because “what’s an open source project without its status page” (and some commercial vendors cough Embarcadero cough could highly benefit from this):
[Wayback/Archive] GitHub – louislam/uptime-kuma: A fancy self-hosted monitoring tool.
Some links (so you can try it for yourself):
- [Wayback/Archive] CryptPad Status (from yesterday’s blog post¹)
- [Wayback/Archive] Uptime Kuma docker site to try yourself
- [Wayback/Archive] Uptime Kuma Demo (starting by choosing a language – many – and database – MariaDB/MySQL or SQLite)
- [Wayback/Archive] Uptime Kuma Status
- [Wayback/Archive] Home · louislam/uptime-kuma Wiki · GitHub
- [Wayback/Archive] uptime-kuma/src/components/notifications at master · louislam/uptime-kuma · GitHub – I like this vast amount of integrations. Some commercial vendors could learn from this.
--jeroen
¹ GitHub – cryptpad/cryptpad: Collaborative office suite, end-to-end encrypted and open-source.
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Posted in *nix, *nix-tools, Development, JavaScript/ECMAScript, Monitoring, Power User, Scripting, Software Development, TypeScript, Vue.js | Leave a Comment »
GitHub – cryptpad/cryptpad: Collaborative office suite, end-to-end encrypted and open-source.
Posted by jpluimers on 2025/11/04
Google Docs alternative for self-hosting or hosted usage: [Wayback/Archive] GitHub – cryptpad/cryptpad: Collaborative office suite, end-to-end encrypted and open-source.
The project started last month 12 years ago in 2014 as the “realtime collaborative visual editor with zero knowlege server” with the commit [Wayback/Archive] and so it begins · cryptpad/cryptpad@1508c7b · GitHub.
Via¹: [Wayback/Archive] Dr. Christopher Kunz: “I’m currently testing Cryptpad for collaborative working.…” – chaos.social
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Posted in *nix, *nix-tools, Cloud, CSS, Development, Google, GoogleDocs, HTML, HTML5, Infrastructure, JavaScript/ECMAScript, Monitoring, Power User, Scripting, Software Development, TypeScript, Web Development | Leave a Comment »
Notes on Oracle Cloud Free Tier (via «I got the “free forever” 4 core/24GB ARM VM from Oracle Cloud. What should I do with it?»)
Posted by jpluimers on 2025/10/02
Some notes (mainly links) on the Oracle Cloud Free Tier as at the time of writing it is the only provider with a “free forever” tier.
In the past for FOSS, there was [Wayback/Archive] Fosshost on Twitter: “@d_feldman Check out fosshost.org for an alternative to Oracle Cloud for ARM/AArch64. We are free, open source and you will never get bill shock. Open source projects must apply only.”, but at the end of 2022 they started to wind down their services as per [Wayback/Archive] Fosshost to Sunset Tenant Services
Fosshost to Sunset Tenant Services
At this time, Fosshost is deeply sorry to announce we are no longer able to continue offering our services.
Because of this, we strongly recommend all Fosshost tenants to backup their data immediately, and migrate elsewhere as soon as possible.
Oh before you begin: if you need a reverse DNS record then be sure to request that as soon as your free tier starts: at that time you have USD 300 credits for running paid services which includes the support to request reverse DNS records.
Anyway, many links on the Oracle OCI Cloud Free Tier (especially the ARM deal is great: lots of RAM as compared to the x86 VMs):
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Posted in CentOS, openSuSE, OracleLinux, RedHat, SuSE Linux, Ubuntu, Uncategorized, Windows, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022 | Leave a Comment »
i-am-shodan/USBArmyKnife: USB Army Knife – the ultimate close access tool for penetration testers and red teamers.
Posted by jpluimers on 2025/09/30
Now that I got pointed to this twice (see “Via” below), I need to get one so I can play with it: [Wayback/Archive] GitHub – i-am-shodan/USBArmyKnife: USB Army Knife – the ultimate close access tool for penetration testers and red teamers.
Via:
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Posted in *nix, *nix-tools, Blue team, Bluetooth, Development, Encryption, ESP32, Hardware, Hardware Development, Hardware Interfacing, Home Audio/Video, HTTPS/TLS security, Infosec (Information Security), Network-and-equipment, Power User, Red team, Software Development, WiFi, Wireshark | Tagged: USBArmyKnife | Leave a Comment »
bash alias to decode email Quoted-Printable stdin data
Posted by jpluimers on 2025/09/25
Perl isn’t my strength, so I was glad to find the below links that inspired me to add this bash function to my profile decoding Quote-Printable email data (for instance used by sendmail and postfix to store SMTP message files):
# https://superuser.com/questions/1452249/fix-revert-wrong-encoding-of-file function sendmail-decode-quoted-printable-from-stdin() { perl -0777 -ne 'use MIME::QuotedPrint; print decode_qp($_)' }
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Posted in *nix, *nix-tools, bash, bash, Development, Perl, Power User, Python, Scripting, sendmail, Software Development | Leave a Comment »
mutool: all purpose tool for dealing with PDF files | mupdf Commands | Man Pages | ManKier
Posted by jpluimers on 2025/09/23
Sometimes I feel like having lived under a rock for ages despite trying to live the command-line life as much as possible.
Anyway: not that long ago I learned about [Wayback/Archive] mutool: all purpose tool for dealing with PDF files | mupdf Commands | Man Pages | ManKier
It is part of [Wayback/Archive] Package mupdf – man pages | ManKier which also has [Wayback/Archive] mupdf: MuPDF is a lightweight PDF viewer written in portable C | mupdf Commands | Man Pages | ManKier.
MuPDF – a kind of sibling to GhostScript – lives at [Wayback/Archive] MuPDF: The ultimate library for managing PDF documents.
The below query got me to [Wayback/Archive] mupdf/docs/man/mutool.1 at master · ccxvii/mupdf · GitHub in the “wrong” repository [Wayback/Archive] GitHub – ccxvii/mupdf: mirrored from git://git.ghostscript.com/mupdf.git
The actual repositories are at:
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Posted in *nix, *nix-tools, Console (command prompt window), Development, PDF, Power User, Scripting, Software Development | Leave a Comment »
Managing the Mail Queue Files and Directories
Posted by jpluimers on 2025/09/15
I wish I had found this overview eons ago: [Wayback/Archive] Managing the Mail Queue Files and Directories.
The most important bits on the various kinds of files that appear in your message queue:
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Posted in *nix, *nix-tools, Power User, sendmail | Leave a Comment »
The Wiert Corner - irregular stream of stuff 