🔧 System

• service pmta restart — restart PowerMTA
• pmta reload — reload configuration without stopping the service
• service pmta start — start PowerMTA
• pmtad --debug — debug mode for troubleshooting
• pmta reset counters — reset statistics counters
• pmta show status — check current service status

📤 Mailing

• pmta pause queue domain.com/vmta — pause sending for a specific VMTA
• pmta pause queue */* — pause all queues
• pmta pause queue domain.com/* — pause by domain
• pmta pause queue */vmta — pause by VMTA
• pmta resume queue domain.com/vmta — resume for a specific VMTA
• pmta resume queue */* — resume all queues
• pmta resume queue domain.com/* — resume by domain
• pmta set queue --mode=normal domain.com/vmta — disable backoff mode for VMTA
• pmta set queue --mode=normal */* — disable backoff mode for all
• pmta delete --queue=gmail.com/* — delete queue by domain
• pmta delete --queue=*/vmta — delete queue by VMTA
• pmta delete --queue=*/* — clear all queues

📊 Statistics

• pmta list --queue=gmail.com — all queues for Gmail
• pmta list --queue=*/* — all queues
• pmta show queues — detailed queue information
• pmta show disabled sources — list of all blocked IPs
• pmta show disabled sources domain.com/* — blocks by domain
• pmta show disabled sources */vmta — blocks by VMTA
• pmta show domains — list of all recipient domains
• pmta show topdomains — most active domains
• pmta show topqueues — queues with highest load
• pmta show vmtas — status of all VMTAs

⚙️ Domain Settings

• pmta show settings domain — basic settings of all domains
• pmta show settings gmail.com/* — settings of a specific domain

📁 Other

• show version — PowerMTA version
• pmta show registration — registration status
• pmta show license — license information

🔧 System

• systemctl restart postfix — restart Postfix service
• systemctl start postfix — start Postfix service
• systemctl stop postfix — stop Postfix service
• systemctl status postfix — check service status
• postfix reload — reload configuration without stopping the service
• postfix check — check configuration for errors
• postconf -n — show only modified settings
• postconf -d — show all default parameters

📤 Mailing

• sendmail user@example.com — send an email manually (body typed after execution)
• mailq — list emails in the queue
• postqueue -p — same as mailq
• postqueue -f — immediately process the queue
• postqueue -s domain.com — send messages only for the specified domain

🛠 Diagnostics & Logs

• tail -f /var/log/mail.log — view mail log in real time
• grep postfix /var/log/mail.log — filter log for Postfix entries
• grep -i "status=" /var/log/mail.log — check email delivery statuses
• postfix -v start — start Postfix in verbose/debug mode

📦 Queue Management

• postsuper -d ALL — delete all messages in the queue
• postsuper -d queue_id — delete a specific message
• postsuper -r queue_id — requeue a specific message
• postsuper -r ALL — requeue all messages
• postsuper -s — check and clean up "dead" messages from the queue

⚙️ Other

• newaliases — rebuild alias database (after editing /etc/aliases)
• postalias /etc/aliases — alternative to newaliases
• postmap /etc/postfix/filename — generate hash map from a config file
• postfix set-permissions — set correct permissions (rarely used)
• postfix upgrade-configuration — upgrade old configs to the new format

🔧 System

• systemctl start dovecot — start the Dovecot service
• systemctl stop dovecot — stop the Dovecot service
• systemctl restart dovecot — restart Dovecot
• systemctl reload dovecot — reload configuration without stopping
• systemctl status dovecot — check Dovecot service status
• doveconf — output the full Dovecot configuration
• doveconf -n — output only non-default (customized) parameters

🛠 Diagnostics & Logs

• tail -f /var/log/mail.log — view mail server logs in real time (usually includes Dovecot)
• journalctl -u dovecot -f — view Dovecot logs via systemd in real time
• doveadm log find — search for errors in Dovecot logs (requires doveadm logging enabled)
• doveadm debug — start Dovecot in debug mode (for testing)

👤 User Management

• doveadm user '*' — list all users
• doveadm user user@example.com — show info for a specific user
• doveadm mailbox list -u user@example.com — list mailboxes for the user

📨 Mail Operations

• doveadm quota get -u user@example.com — show the user's quota
• doveadm expunge -u user@example.com mailbox INBOX savedbefore 30days — delete emails older than 30 days from INBOX
• doveadm fetch savedate mailbox INBOX all — show saved date of all emails in INBOX

⚙️ Other

• doveadm auth test user@example.com password — test user authentication with a given password
• doveadm ssl generate — generate an SSL certificate for Dovecot (if not using an external one)
• doveadm config get — get values of specific configuration parameters

🔧 System

• systemctl start fail2ban — Start Fail2ban
• systemctl stop fail2ban — Stop Fail2ban
• systemctl restart fail2ban — Restart Fail2ban
• systemctl status fail2ban — Check Fail2ban status

🚫 Ban Management

• fail2ban-client status — General Fail2ban status
• fail2ban-client status <jail_name> — Status of a specific jail
• fail2ban-client set <jail_name> banip <IP_address> — Manually ban an IP
• fail2ban-client set <jail_name> unbanip <IP_address> — Unban an IP
• fail2ban-client reload — Reload configuration

🕵️‍♂️ Diagnostics

• journalctl -u fail2ban -f — View logs in real time
• fail2ban-client ping — Check if the daemon is running

▶️ Start and Stop

• systemctl start spamassassin — Start SpamAssassin
• systemctl stop spamassassin — Stop SpamAssassin
• systemctl restart spamassassin — Restart SpamAssassin
• systemctl status spamassassin — Check service status

⬆️ Update and Check

• sa-update — Update SpamAssassin rules
• spamassassin -t < email.eml — Test an email for spam
• spamc < email.eml — Quick spam test using client

🔍 Diagnostics and Configuration

• spamassassin --lint — Check configuration for errors
• spamassassin --dump-headers — Output all headers used for filtering
• spamassassin --version — Show SpamAssassin version

🔧 System

• systemctl start opendkim — Start OpenDKIM
• systemctl stop opendkim — Stop OpenDKIM
• systemctl restart opendkim — Restart OpenDKIM
• systemctl status opendkim — Check service status

⚙️ Configuration

• nano /etc/opendkim.conf — Main configuration file
• nano /etc/opendkim/KeyTable — Key table
• nano /etc/opendkim/SigningTable — Signing table (domains to sign)
• nano /etc/opendkim/TrustedHosts — Trusted hosts

🛠️ Key Generation

• opendkim-genkey -s mail -d example.com — Generate DKIM key
• cat mail.txt — View DKIM DNS record

🕵️‍♂️ Diagnostics

• journalctl -u opendkim -f — View logs in real time
• opendkim-testkey -d example.com -s mail -vvv — Test DKIM key

📦 Installation

• apt install apache2 — Install on Debian/Ubuntu
• dnf install httpd — Install on AlmaLinux/CentOS/RHEL

🔧 Service Management

• systemctl start apache2 — Start Apache (Debian)
• systemctl start httpd — Start Apache (AlmaLinux)
• systemctl restart apache2 — Restart (Debian)
• systemctl restart httpd — Restart (AlmaLinux)
• systemctl status apache2 — Status (Debian)
• systemctl status httpd — Status (AlmaLinux)

🛠️ Configuration

• /etc/apache2/apache2.conf — Main config (Debian)
• /etc/httpd/conf/httpd.conf — Main config (AlmaLinux)
• /etc/apache2/sites-available — Virtual hosts (Debian)
• /etc/httpd/conf.d — Virtual hosts (AlmaLinux)

🚀 Site Management Commands (Debian only)

• a2ensite site.conf — Enable a site
• a2dissite site.conf — Disable a site
• a2enmod rewrite — Enable a module
• a2dismod rewrite — Disable a module

🧪 Testing and Restart

• apachectl configtest — Test configuration
• apachectl graceful — Graceful restart
• journalctl -u apache2 -f — Real-time logs (Debian)
• journalctl -u httpd -f — Real-time logs (AlmaLinux)