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