Table of Contents
Ubuntu
Open lightsail ports SSH TCP 22 Custom TCP 25 HTTP TCP 80 Custom TCP 110 Custom TCP 143 HTTPS TCP 443 Custom TCP 993 Custom TCP 995
sudo netstat -lnpt Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 127.0.0.1:3306 0.0.0.0:* LISTEN 4786/mysqld tcp 0 0 0.0.0.0:110 0.0.0.0:* LISTEN 5971/dovecot tcp 0 0 0.0.0.0:143 0.0.0.0:* LISTEN 5971/dovecot tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 926/nginx -g daemon tcp 0 0 0.0.0.0:22 0.0.0.0:* LISTEN 1194/sshd tcp 0 0 0.0.0.0:25 0.0.0.0:* LISTEN 907/master tcp 0 0 0.0.0.0:443 0.0.0.0:* LISTEN 926/nginx -g daemon tcp6 0 0 :::110 :::* LISTEN 5971/dovecot tcp6 0 0 :::143 :::* LISTEN 5971/dovecot tcp6 0 0 :::80 :::* LISTEN 926/nginx -g daemon tcp6 0 0 :::22 :::* LISTEN 1194/sshd tcp6 0 0 :::25 :::* LISTEN 907/master tcp6 0 0 :::443 :::* LISTEN 926/nginx -g daemon
DNS settings (Route53) hensler.net. MX 10 mail.hensler.net 202.201.225.3.in-addr.arpa.hensler.net. PTR ec2-3-225-201-202.compute-1.amazonaws.com mail.hensler.net. A 3.225.201.202
Local Firewall disabled > lightsail firewall sudo ufw status Status: inactive sudo service iptables status ● iptables.service Loaded: not-found (Reason: No such file or directory) Active: inactive (dead)
nc -z mail.hensler.net 110
Create Mail user sudo useradd -m -G mail -s /bin/bash/ bernhard sudo passwd bernhard sudo deluser --remove-home gabriel sudo apt install mailutils su bernhard Cannot execute /bin/bash/: Not a directory sudo chsh -s /bin/bash bernhard // > remove /
Postfix
Postfix setup sudo apt install postfix sudo postconf mail_version sudo service postfix restart dpkg -L postfix | grep /usr/sbin/ sudo vim /etc/postfix/main.cf sudo dpkg-reconfigure postfix sudo postconf -e 'home_mailbox = Maildir/' sudo postconf -e 'mydomain = hensler.net' sudo postconf -e 'smtpd_tls_cert_file = /etc/letsencrypt/live/hensler.net/fullchain.pem' sudo postconf -e 'smtpd_tls_key_file = /etc/letsencrypt/live/hensler.net/privkey.pem' ... many others, refer to afore mentioned website. sudo vim /etc/postfix/virtual postmaster@example.com root root@example.com root info@exampe.com info sudo postmap /etc/postfix/virtual sudo systemctl restart postfix tail -f /var/log/syslog | grep postfix vim /var/log/mail.log
list queued messages stuck sudo mailq Scenario 1 : Remove particular mail queue id (on running mailq command,you will get mail queue id) postsuper -d mail_queue_id Scenario 2: Remove ALL mails from queue postsuper -d ALL Scenario 3: Remove only ALL deferred mails which are in queue postsuper -d ALL deferred
Dovecot
Dovecot setup sudo apt-get install dovecot-imapd dovecot-pop3d sudo vim /etc/dovecot/dovecot.conf Most of the actual configuration gets included below sudo vim /etc/dovecot/conf.d/10-auth.conf disable_plaintext_auth = yes auth_mechanisms = plain login sudo vim /etc/dovecot/conf.d/10-mail.conf mail_location = maildir:~/Maildir sudo vim /etc/dovecot/conf.d/10-ssl.conf ssl = required ssl_cert = </etc/letsencrypt/live/hensler.net/fullchain.pem ssl_key = </etc/letsencrypt/live/hensler.net/privkey.pem openssl rsa -in /etc/letsencrypt/live/mail.hensler.net/privkey.pem -check -noout sudo service dovecot restart
SMTP Banner
sudo vim /etc/postfix/main.cf
smtpd_banner = ec2-3-225-201-202.compute-1.amazonaws.com ESMTP $mail_name (Ubuntu)nc mail.hensler.net 25
220 ec2-3-225-201-202.compute-1.amazonaws.com ESMTP Postfix (Ubuntu)202.201.225.3.in-addr.arpa.hensler.net. PTR ec2-3-225-201-202.compute-1.amazonaws.com
Test connections: https://mxtoolbox.com/SuperTool.aspx