Postfix /etc/postfix/main.cf

Authentic ๐Ÿ“‹ Ubuntu 20.04 LTS (Focal Fossa) 47 lines

File Info

Size
47 lines
MD5
944782d8918fdf2cedeb1edac1f5c21c
SHA256
0bfd753514d2cf06b68fdaef4d7f75bb73dede55bc28bcd61f63e3df2a127fff

Quick Commands

curl:
curl https://exampleconfig.com/api/v1/config/original/944782d8918fdf2cedeb1edac1f5c21c?hint=main.cf
wget:
wget -O main.cf https://exampleconfig.com/api/v1/config/original/944782d8918fdf2cedeb1edac1f5c21c?hint=main.cf
/etc/postfix/main.cf
# See /usr/share/postfix/main.cf.dist for a commented, more complete version


# Debian specific:  Specifying a file name will cause the first
# line of that file to be used as the name.  The Debian default
# is /etc/mailname.
#myorigin = /etc/mailname

smtpd_banner = $myhostname ESMTP $mail_name (Ubuntu)
biff = no

# appending .domain is the MUA's job.
append_dot_mydomain = no

# Uncomment the next line to generate "delayed mail" warnings
#delay_warning_time = 4h

readme_directory = no

# See http://www.postfix.org/COMPATIBILITY_README.html -- default to 2 on
# fresh installs.
compatibility_level = 2



# TLS parameters
smtpd_tls_cert_file=/etc/ssl/certs/ssl-cert-snakeoil.pem
smtpd_tls_key_file=/etc/ssl/private/ssl-cert-snakeoil.key
smtpd_tls_security_level=may

smtp_tls_CApath=/etc/ssl/certs
smtp_tls_security_level=may
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache


smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = 4f82985f8468
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = $myhostname, 4f82985f8468, localhost.localdomain, , localhost
relayhost = 
mynetworks = 127.0.0.0/8 [::ffff:127.0.0.0]/104 [::1]/128
mailbox_size_limit = 0
recipient_delimiter = +
inet_interfaces = all
inet_protocols = all

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/postfix/main.cf
Directory
/etc/postfix/
Significance
System-wide configuration directory
Description
Files in /etc/ contain system-wide configuration settings that affect all users.

Complete Postfix Configuration Guide

What is main.cf?
Download the original 'main.cf' (main.cf) configuration file from a fresh Postfix installation on Ubuntu 20.04 LTS (Focal Fossa). 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/postfix/main.cf', this 47-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 Ubuntu 20.04?
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 main.cf 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/postfix/main.cf. Make sure to backup your existing configuration first, then restart the Postfix service to apply the changes.

Is this main.cf file secure for production use?

This is the factory-default configuration that ships with Postfix on Ubuntu 20.04 LTS (Focal Fossa). 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 Ubuntu 20.04 LTS (Focal Fossa). 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.