This is an old revision of the document!
# 1. Main configuration
cat << 'EOF' | sudo tee /etc/exim4/update-exim4.conf.conf dc_eximconfig_configtype='satellite' dc_smarthost='mail.haacksnetworking.org::587' dc_local_interfaces='127.0.0.1 ; ::1' dc_other_hostnames='' dc_readhost='haacksnetworking.org' dc_relay_domains='' dc_minimaldns='false' dc_hide_mailname='true' dc_localdelivery='net@haacksnetworking.org' EOF
# 2. Local macros
cat << 'EOF' | sudo tee /etc/exim4/exim4.conf.localmacros MAIN_TLS_ADVERTISE_HOSTS = REMOTE_SMTP_SMARTHOST_HOSTS_REQUIRE_TLS = * MAIN_LOCAL_DOMAINS = disable_ipv6 = true EOF
# 3. Password file
cat << 'EOF' | sudo tee /etc/exim4/passwd.client mail.haacksnetworking.org:net:pass *:net:pass EOF
# 4. Email address rewriting
cat << 'EOF' | sudo tee /etc/email-addresses sexa: net@haacksnetworking.org root: net@haacksnetworking.org *: net@haacksnetworking.org EOF
# 5. Set mailname
echo "net.outsidebox.vip" | sudo tee /etc/mailname echo "net.outsidebox.vip" | sudo tee /etc/hostname
Make sure alias and fqdn are also specified properly in /etc/hosts.
# 6. Fix permissions and apply
sudo chown root:Debian-exim /etc/exim4/passwd.client sudo chmod 640 /etc/exim4/passwd.client sudo update-exim4.conf sudo systemctl restart exim4
# 7. Configure the remote mailserver to accept email from the subdomain and/or other IP of the client:
nano /etc/postfix/main.cf
mydestination = mail.haacksnetworking.org,
haacksnetworking.org,
mail.haacksnetworking.org,
node0.otherdomain.org, #accept system email sent to your node's "local" address
node1.otherdomain.com, #accept system email sent to your node's "local" address
localhost.haacksnetworking.org,
localhost
sudo systemctl restart postfix
System emails default to root@sub.domain.org or root@net.outsidebox.vip for example. Unless you approve that envelope, the message will be rejected. If you approve it like in my example above, then mail.haacksnetworking.org accepts the email for the corresponding “user” or in this case “net”. If you also want to send and respond and use this subdomain in webmail, you can set up A/MX and do so (I'm not). The point of this last part is just that it ensures system email from root@whatevernode.whateverdomain.com arrives to the corresponding user on mail.haacksnetworking.org. In my case, that's typically “root” and then root is aliased to notifications@haacksnetworking.org. In this way, every node feeds into a common monitoring email/system.
— oemb1905 2026/04/19 02:38
