# Postfix Published articles for Postfix. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## Postfix on Kubernetes: A Step-by-Step Email Guide DevFeed: [Postfix on Kubernetes: A Step-by-Step Email Guide]() Original publisher: [Read original article]() Author: RisingStack Engineering Published: 2025-09-25T04:12:00Z Content type: tutorial Language: en Sources: [RisingStack]() Topics: [Kubernetes](), [email](), [Authorization]() Tags: [authentication](), [email](), [guide](), [kubernetes](), [postfix](), [spoofing]() ### AI overview A step-by-step guide to running a Postfix email server on Kubernetes. It explains the infrastructure and email-authentication requirements, including a fixed outbound IP address, a domain, PTR and SPF records, and DKIM and DMARC configuration. ### Source excerpt You are in the process of putting together your application. While designing your authorization solution, you realize you will need to send emails to potential clients.Using a third-party service (like SendGrid or Mailgun) to cover your needs for now looks pretty attractive. After all, you don't have any users yet, they offer free tiers, and [...] The post Postfix on Kubernetes: A Step-by-Step Email Guide appeared first on RisingStack Engineering. ## GKE in production DevFeed: [GKE in production]() Original publisher: [Read original article]() Author: Carlos Alexandro Becker Published: 2017-07-02T00:00:00Z Content type: tutorial Language: en Sources: [Carlos Becker]() Topics: [Gke](), [Google Cloud Platform (GCP)](), [Kubernetes](), [Amazon Web Services](), [Digital Ocean]() Tags: [aws](), [cloud-sql](), [digitalocean](), [gke](), [google-cloud](), [health-checks](), [heroku](), [ingress](), [kubernetes](), [postfix](), [sendgrid](), [spinnaker]() ### AI overview A developer describes deploying small applications on GKE and lessons learned from moving between AWS and Google Cloud. The article covers SSL with Kubernetes Ingress, email delivery through SendGrid, Cloud SQL access through a sidecar container, and deployment with a shell script or Spinnaker. ### Source excerpt I've been working with DigitalOcean, Heroku and AWS for some years now. ## Postfix - automatically drop outbound mail DevFeed: [Postfix - automatically drop outbound mail]() Original publisher: [Read original article]() Author: Tom Published: 2014-03-18T00:00:00Z Content type: tutorial Language: en Sources: [Tomasz Gągor]() Topics: [Development](), [Server]() Tags: [debug](), [development](), [linux](), [logs](), [mail](), [postfix](), [server](), [test]() ### AI overview A configuration tutorial for Postfix on a development server. It shows how to permit outbound mail to one domain while discarding mail sent to all other destinations, then reload and test the configuration. ### Source excerpt I have development server with postfix - I wanted to allow outbound traffic to one domain but cut off all the rest. I definitely do not want that test mail or any debug info goes to service users. I have to add something like that to /etc/postfix/transport: allowed.domain.com : * discard: Then run: postmap /etc/postfix/transport At end, add these to /etc/postfix/main.cf: transport_maps = hash:/etc/postfix/transport Reload postfix: postfix reload Test if it works: ## Postfix: ciekawy problem z smtpd\_delay\_reject i permit\_sasl\_authenticated DevFeed: [Postfix: ciekawy problem z smtpd\_delay\_reject i permit\_sasl\_authenticated]() Original publisher: [Read original article]() Author: Tom Published: 2013-10-08T00:00:00Z Content type: tutorial Language: pl Sources: [Tomasz Gągor]() Topics: [SSL](), [client]() Tags: [debug](), [linux](), [postfix](), [sasl](), [smtp](), [ssl]() ### AI overview A troubleshooting article about a Postfix configuration problem involving smtpd_delay_reject and permit_sasl_authenticated. Changing the restriction ordering resolved authentication failures for SSL SMTP submissions, and the author also addressed a user-spoofing issue. ### Source excerpt Trafił mi się ostatnio ciekawy problem - otóż standardowo przed końcem roku poprawiałem filtry antyspamowe i optymalizowałem konfigurację Postfix'a. Chciałem zmienić domyślną wartość smtpd_delay_reject=yes na smtpd_delay_reject=no by odrzucać spamerów najwcześniej jak to możliwe. I ciekawe kuku, które sobie zrobiłem polegało na tym że sam nie mogłem wysyłać poczty po logowaniu SSL'em... Dostawałem przy tym bardzo wymowną odpowiedź: Oct 8 16:30:39 tyr postfix/smtpd[21039]: NOQUEUE: reject: CONNECT from unknown[67.x.x.x]: 554 5.7.1 : Client host rejected: Access denied; proto=SMTP Więc wrzuciłem debug_peer_list = 67.x.x.x do main.cf by zobaczyć dokładniej o co biega: ## Ochrona usług przed atakami brute force z fail2ban'em DevFeed: [Ochrona usług przed atakami brute force z fail2ban'em]() Original publisher: [Read original article]() Author: Tom Published: 2011-10-03T00:00:00Z Content type: tutorial Language: pl Sources: [Tomasz Gągor]() Topics: [Fail2ban](), [Logging](), [ssh]() Tags: [admin](), [apache](), [debian](), [fail2ban](), [linux](), [postfix](), [sasl](), [security](), [spam](), [ssh](), [syslog]() ### AI overview This Polish article explains how Fail2ban can monitor authentication failures in syslog and protect publicly accessible services from brute-force attacks and other abusive activity. It discusses basic configuration, supported services, modular filters and actions, performance considerations, and installation on Debian. ### Source excerpt Bardzo często konfigurując usługi dostępne publicznie poświęca się sporo czasu na maksymalne zwiększenie bezpieczeństwa przez "dopieszczanie" konfiguracji (certyfikaty z mocnym szyfrowaniem, ochronę pewnych stron hasłem, dostęp do SSH tylko kluczami, itd.) ale całkowicie pomija się przygotowanie systemu aktywnie monitorującego błędne próby autoryzacji. Oczywiście nie można umniejszać wagi pierwszego z wymienionych etapów ale zdecydowanie nie powinno pomijać się też tego drugiego. Przecież każdy admin chciałby wiedzieć gdy ktoś próbuje włamać się na jego serwer (FTP, HTTP, SSH, itp.) - tylko ilu z Nas zadaje sobie trud by uruchomić taki system? ## pflogsumm - Mail Statistics for Postfix DevFeed: [pflogsumm - Mail Statistics for Postfix]() Original publisher: [Read original article]() Author: Tom Published: 2011-09-22T00:00:00Z Content type: tutorial Language: en Sources: [Tomasz Gągor]() Topics: [monitor](), [Server]() Tags: [command](), [generate](), [health](), [how-to](), [installation](), [linux](), [linux-mail-tools](), [logs](), [mail](), [mail-server-management](), [monitor](), [pflogsumm](), [postfix](), [postfix-log-analysis](), [postfix-mail-statistics](), [postfix-monitoring](), [process](), [reporting](), [review](), [run](), [server](), [standard](), [statistics](), [volume]() ### AI overview A tutorial on using pflogsumm with Postfix logs to generate mail statistics for reviewing a mail server's health, traffic, and communication issues. It covers Debian installation, command-line use, log rotation, and periodic cron-based reporting. ### Source excerpt Learn how to use pflogsumm to generate comprehensive mail statistics for Postfix, helping you monitor and manage your mail server effectively. ## Postfix sender\_dependent\_relayhost\_maps DevFeed: [Postfix sender\_dependent\_relayhost\_maps]() Original publisher: [Read original article]() Author: Dimitri Fontaine PostgreSQL Major Contributor; Author Published: 2010-09-23T12:30:00Z Content type: tutorial Language: en Sources: [Dimitri Fontaine]() Topics: [email](), [Unix](), [Server](), [ssh]() Tags: [email](), [password](), [postfix](), [server](), [setup](), [ssh](), [trust](), [unix]() ### AI overview A tutorial on configuring Postfix to use different relay hosts based on the sender's From address, such as separating personal and work email. It also discusses generating map and password files and encrypting communication with the relay host. ### Source excerpt The previous article about M-x mailq has raised several mails asking me details about the Postfix setup I'm talking about. The problem we're trying to solve is having a local MTA to send mails, so that any old-style Unix tool just works, instead of only the MUA you've spent time setting up. Postfix makes it possible to do that quite easily, but it gets a little more involved if you have more than one relayhost that you want to use depending on your current From address. Think personal email against work email, or avoiding your ISP network when sending your private mails, hoping directly on a server you own or trust. ## Scratch that itch: M-x mailq DevFeed: [Scratch that itch: M-x mailq]() Original publisher: [Read original article]() Author: Dimitri Fontaine PostgreSQL Major Contributor; Author Published: 2010-09-23T07:30:00Z Content type: tutorial Language: en Sources: [Dimitri Fontaine]() Topics: [email](), [Command-line interface](), [Unix](), [Authentication]() Tags: [authentication](), [command](), [email](), [postfix](), [queue](), [shell](), [smtp](), [systems](), [terminal]() ### AI overview The article introduces M-x mailq, an Emacs command for viewing and flushing the Postfix mail queue. It addresses mail queued during unavailable relay tunnels and describes inspecting or selectively managing queued messages. ### Source excerpt Nowadays, most people would think that email is something simple, you just setup your preferred client (that's called a MUA) with some information such as the smtp host you want it to talk to (that's call a MTA and this one is your relayhost). Then there's all the receiving mails part, and that's smtp again on the server side. Then there's how to get those mail, read them, flag them, manage them, and that's better served by IMAP. Let's talk about sending mails in smtp for this entry.