Postfix /etc/systemd/postfix@.service

Authentic ๐Ÿ“‹ Debian 9 (Stretch) 20 lines

Compatibility

Currently viewing:
Debian 9 (Stretch)
Also compatible:
Debian 10 (Buster) Debian 11 (Bullseye) Debian 12 (Bookworm) Ubuntu 18.04 LTS (Bionic Beaver) Ubuntu 20.04 LTS (Focal Fossa) Ubuntu 22.04 LTS (Jammy Jellyfish) Ubuntu 24.04 LTS (Noble Numbat)
Different versions:

File Info

Size
20 lines
MD5
4224e053e1fa1cb321f51b18026bb698
SHA256
01730141e4cda8aa4240438c09e52746e5c61672a854f683469659be7ae9f7b5

Quick Commands

curl:
curl https://exampleconfig.com/api/v1/config/original/4224e053e1fa1cb321f51b18026bb698?hint=postfix@.service
wget:
wget -O postfix@.service https://exampleconfig.com/api/v1/config/original/4224e053e1fa1cb321f51b18026bb698?hint=postfix@.service
/etc/systemd/postfix@.service
[Unit]
Description=Postfix Mail Transport Agent (instance %i)
Documentation=man:postfix(1)
PartOf=postfix.service
Before=postfix.service
ReloadPropagatedFrom=postfix.service
After=network-online.target nss-lookup.target
Wants=network-online.target

[Service]
Type=forking
GuessMainPID=no
ExecStartPre=/usr/lib/postfix/configure-instance.sh %i
ExecStart=/usr/sbin/postmulti -i %i -p start
ExecStop=/usr/sbin/postmulti -i %i -p stop
ExecReload=/usr/sbin/postmulti -i %i -p reload

[Install]
WantedBy=multi-user.target

How to Install Postfix

Alpine Linux

sudo apk add postfix

Debian

sudo apt update && sudo apt install postfix

Red Hat Enterprise Linux

sudo yum install postfix

Ubuntu

sudo apt update && sudo apt install postfix

Configuration File Location

File Path
/etc/systemd/postfix@.service
Directory
/etc/systemd/
Significance
System-wide configuration directory
Description
Files in /etc/ contain system-wide configuration settings that affect all users.

Complete Postfix Configuration Guide

What is postfix@.service?
Download the original 'postfix@.service' (main.cf) configuration file from a fresh Postfix installation on Debian 9 (Stretch). This is the factory-default mail server configuration, essential for email system recovery, anti-spam setup, and understanding secure mail relay settings.
Technical Details
Located at '/etc/systemd/postfix@.service', this 20-line file controls SMTP authentication, TLS encryption, spam filtering, mail routing, and delivery policies. Powers email infrastructure for millions of domains and handles everything from personal mail servers to enterprise email systems processing thousands of messages daily.
Common Configuration Question
How do you configure Postfix for secure mail delivery, spam prevention, and high availability on Debian 9?
Why Use This Configuration?
This default configuration includes SPF/DKIM support, TLS encryption, and anti-spam measures. Critical for email administrators, system administrators, and DevOps engineers managing production mail infrastructure.

Frequently Asked Questions

When should I use this postfix@.service file?

Use this original configuration file when you need to restore Postfix to its default state after misconfiguration, during fresh installations, or as a baseline for customization. It's particularly useful for troubleshooting when your current config isn't working properly.

How do I restore Postfix to default settings?

Download this file and replace your current configuration at /etc/systemd/postfix@.service. Make sure to backup your existing configuration first, then restart the Postfix service to apply the changes.

Is this postfix@.service file secure for production use?

This is the factory-default configuration that ships with Postfix on Debian 9 (Stretch). While it provides a secure baseline, you should review and customize security settings based on your specific production requirements and compliance needs.

What's the difference between this and other OS versions?

This configuration is specifically from Debian 9 (Stretch). Different operating systems and versions may have slightly different default settings, security patches, or feature availability. Check the compatibility section above for other OS versions.

Can I use this configuration file for Postfix troubleshooting?

Yes, this original configuration is excellent for troubleshooting. Compare it with your current settings to identify modifications that might be causing issues, or temporarily replace your config with this one to isolate problems.