Postfix /etc/postfix/main.cf

Original 📋 Debian 10 (Buster) 46 lines
/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 (Debian/GNU)
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_use_tls=yes
smtpd_tls_session_cache_database = btree:${data_directory}/smtpd_scache
smtp_tls_session_cache_database = btree:${data_directory}/smtp_scache

# See /usr/share/doc/postfix/TLS_README.gz in the postfix-doc package for
# information on enabling SSL in the smtp client.

smtpd_relay_restrictions = permit_mynetworks permit_sasl_authenticated defer_unauth_destination
myhostname = 48baa2c5067c
alias_maps = hash:/etc/aliases
alias_database = hash:/etc/aliases
mydestination = $myhostname, 48baa2c5067c, 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

Copy & Paste

curl:
curl https://exampleconfig.com/api/v1/config/original/1c50ee760a0871fa028ee7e849262cf1?hint=main.cf
wget:
wget -O main.cf https://exampleconfig.com/api/v1/config/original/1c50ee760a0871fa028ee7e849262cf1?hint=main.cf

For AI Agents

<prompt><role>DevOps agent</role><source url='https://exampleconfig.com/api/v1/config/original/1c50ee760a0871fa028ee7e849262cf1?hint=main.cf' /><config><app>Postfix</app><os>Debian 10 (Buster)</os><location>/etc/postfix/main.cf</location><lines>46</lines><md5>1c50ee760a0871fa028ee7e849262cf1</md5><sha256>1fd567d142d1d7ce07b7adc140a8032f81eabf88bb468a10c4a77032e8dad653</sha256></config></prompt>

Paste into Claude, ChatGPT, or any AI assistant.

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

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.

FAQ

When should I use this main.cf?

Use it to restore a missing default, confirm what shipped, or diff against your current Postfix config.

How do I restore Postfix defaults?

Download the file, back up the current one in /etc/postfix/main.cf, replace it, then reload or restart Postfix.

Is main.cf safe for production?

It is the vendor default for Debian 10 (Buster). Treat it as a baseline and review security and performance settings before production use.

How does this differ from other OS versions?

Defaults vary by distro and version. This copy matches Debian 10 (Buster).

Can I use this for Postfix troubleshooting?

Yes. Diff it against yours to find drift, then restore only the sections you need.