fruitbasket/modules/mail/postfix.nix

107 lines
3.9 KiB
Nix

{ config, pkgs, ... }:
let
domain = config.networking.domain;
hostname = "mail.${config.networking.domain}";
# see https://www.kuketz-blog.de/e-mail-anbieter-ip-stripping-aus-datenschutzgruenden/
header_cleanup = pkgs.writeText "header_cleanup_outgoing" ''
/^\s*(Received: from)[^\n]*(.*)/ REPLACE $1 127.0.0.1 (localhost [127.0.0.1])$2
/^\s*User-Agent/ IGNORE
/^\s*X-Enigmail/ IGNORE
/^\s*X-Mailer/ IGNORE
/^\s*X-Originating-IP/ IGNORE
/^\s*Mime-Version/ IGNORE
'';
# https://unix.stackexchange.com/questions/294300/postfix-prevent-users-from-changing-the-real-e-mail-address
login_maps = pkgs.writeText "login_maps.pcre" ''
# basic username => username@ifsr.de
/^([^@+]*)(\+[^@]*)?@ifsr\.de$/ ''${1}
'';
in
{
sops.secrets."postfix_ldap_aliases".owner = config.services.postfix.user;
networking.firewall.allowedTCPPorts = [
25 # SMTP
465 # Submissions
587 # Submission
];
services = {
postfix = {
enable = true;
enableSubmission = true;
enableSubmissions = true;
hostname = "${hostname}";
domain = "${domain}";
origin = "${domain}";
destination = [ "${hostname}" "${domain}" "localhost" ];
networksStyle = "host"; # localhost and own public IP
sslCert = "/var/lib/acme/${hostname}/fullchain.pem";
sslKey = "/var/lib/acme/${hostname}/key.pem";
relayDomains = [ "hash:/var/lib/mailman/data/postfix_domains" ];
config = {
home_mailbox = "Maildir/";
# 25 MiB
message_size_limit = "26214400";
# hostname used in helo command. It is recommended to have this match the reverse dns entry
smtp_helo_name = config.networking.rDNS;
smtpd_banner = "${config.networking.rDNS} ESMTP $mail_name";
smtp_use_tls = true;
# smtp_tls_security_level = "encrypt";
smtpd_use_tls = true;
# smtpd_tls_security_level = lib.mkForce "encrypt";
# smtpd_tls_auth_only = true;
smtpd_tls_protocols = [
"!SSLv2"
"!SSLv3"
"!TLSv1"
"!TLSv1.1"
];
# "reject_non_fqdn_hostname"
smtpd_recipient_restrictions = [
"permit_sasl_authenticated"
"permit_mynetworks"
"reject_unauth_destination"
"reject_non_fqdn_sender"
"reject_non_fqdn_recipient"
"reject_unknown_sender_domain"
"reject_unknown_recipient_domain"
"reject_unauth_destination"
"reject_unauth_pipelining"
"reject_invalid_hostname"
"check_policy_service inet:localhost:12340"
];
smtpd_relay_restrictions = [
"permit_sasl_authenticated"
"permit_mynetworks"
"reject_unauth_destination"
];
# https://www.postfix.org/smtp-smuggling.html
smtpd_data_restrictions = [
"reject_unauth_pipelining"
];
smtpd_sender_restrictions = [
"reject_authenticated_sender_login_mismatch"
];
smtpd_sender_login_maps = [
"pcre:/etc/special-aliases.pcre"
"pcre:${login_maps}"
];
smtp_header_checks = "pcre:${header_cleanup}";
# smtpd_sender_login_maps = [ "ldap:${ldap-senders}" ];
alias_maps = [ "hash:/etc/aliases" ];
alias_database = [ "hash:/etc/aliases" ];
# alias_maps = [ "hash:/etc/aliases" "ldap:${ldap-aliases}" ];
smtpd_sasl_auth_enable = true;
smtpd_sasl_path = "/var/lib/postfix/auth";
smtpd_sasl_type = "dovecot";
#mailman stuff
mailbox_transport = "lmtp:unix:/run/dovecot2/dovecot-lmtp";
transport_maps = [ "hash:/var/lib/mailman/data/postfix_lmtp" ];
virtual_alias_maps = [ "hash:/var/lib/mailman/data/postfix_vmap" ];
local_recipient_maps = [ "hash:/var/lib/mailman/data/postfix_lmtp" "ldap:${config.sops.secrets."postfix_ldap_aliases".path}" "$alias_maps" ];
};
};
};
}