Cwp Email

CWP Email Management

Manage Postfix, Dovecot, Roundcube, spam filtering, and email authentication on CWP servers. Handle mail delivery issues, queue management, and security configuration.

Email Components

Service Detection

Detect which email services are installed:

# SpamAssassin (optional)
systemctl is-active spamassassin 2>/dev/null && echo "SpamAssassin: active" || echo "SpamAssassin: not installed"

# ClamAV (optional)
systemctl is-active clamd 2>/dev/null && echo "ClamAV: active" || echo "ClamAV: not installed"

# Rspamd (optional)
systemctl is-active rspamd 2>/dev/null && echo "Rspamd: active" || echo "Rspamd: not installed"

# Policyd (optional)
systemctl is-active cbpolicyd 2>/dev/null && echo "Policyd: active" || echo "Policyd: not installed"

Configuration Files

Service Management

# Postfix
systemctl restart postfix
systemctl status postfix

# Dovecot
systemctl restart dovecot
systemctl status dovecot

# SpamAssassin
systemctl restart spamassassin

# ClamAV
systemctl restart clamd

# Policyd
service cbpolicyd start|stop|restart|status

Email Authentication

SPF (Sender Policy Framework)

SPF records are added as DNS TXT records:

v=spf1 +a +mx +ip4:SERVER_IP ~all

DKIM (DomainKeys Identified Mail)

Configure DKIM per domain via CWP. Generate and manage keys through the CWP Admin panel under Email -> DKIM Manager.

DMARC

Add as DNS TXT record:

v=DMARC1; p=quarantine; rua=mailto:admin@domain.com; pct=100

Email Rate Limiting

Install Policyd

sh /scripts/install_cbpolicyd

Configure Rate Limits

# Update limits for all domains
/scripts/cwp_api account update_policyd_all

# Default: 250 emails/hour per account
# Database: postfix_policyd

Rspamd (SpamAssassin Alternative)

Rspamd is a lightweight alternative that reduces resource usage significantly:

Rspamd is recommended for email forwarding scenarios requiring ARC signing.

Mail Queue Management

# View mail queue
postqueue -p

# Check mail queue stats
/scripts/mail_queue_stats

# Flush mail queue
postfix flush

# Delete all queued mail
postsuper -d ALL

# Delete deferred mail
postsuper -d ALL deferred

# Check mail queue
/scripts/check_postqueue

# Hold specific message
postsuper -h MESSAGE_ID

# Release held message
postsuper -H MESSAGE_ID

Email Storage

• Location: /var/vmail/DOMAIN/USER/
• Format: Maildir format
• Permissions: Managed by Dovecot

Roundcube Webmail

• URL: https://SERVER_IP:2096
• Update: /scripts/mail_roundcube_update

Common Issues and Solutions

Can't Send Emails

1. Verify DKIM, SPF, and DMARC records are correct
2. Check rDNS (reverse DNS) matches mail hostname
3. Check IP against blacklists (MXToolbox)
4. Verify Postfix is running: systemctl status postfix

Amavisd 100% CPU

# Disable Bayesian filtering
echo "use_bayes 0" >> /etc/mail/spamassassin/local.cf
systemctl restart spamassassin

DKIM Double Signature

Prevent double DKIM signing when using AMaViS or OpenDKIM together. Edit /etc/postfix/master.cf:

# Find the smtp line and add no_milters
# Before:
# smtp      inet  n       -       n       -       -       smtpd

# After:
# smtp      inet  n       -       n       -       -       smtpd -o content_filter= -o smtpd_milters= -o non_smtpd_milters=

# Or add to the pickup service:
# pickup    unix  n       -       n       60      1       pickup
#   -o content_filter=
#   -o receive_override_options=no_header_body_checks,no_milters

Then restart Postfix:

systemctl restart postfix

Roundcube Errors

# Update Roundcube
/scripts/mail_roundcube_update

# Fix mail permissions
/scripts/cwp_api account mail_fix_permissions

SpamAssassin start-limit-hit

# Add to systemd service override
# StartLimitBurst=0
systemctl daemon-reload
systemctl restart spamassassin

Mail Permission Issues

# Fix mail permissions for all accounts
/scripts/cwp_api account mail_fix_permissions

# Fix specific user
/scripts/cwp_api account fix_perms USERNAME

Sender Blacklist/Whitelist

Edit /etc/postfix/sender_blacklist and /etc/postfix/sender_whitelist:

# Blacklist format
bad@spammer.com    REJECT

# Whitelist format
good@sender.com    OK

After editing:

postmap /etc/postfix/sender_blacklist
postmap /etc/postfix/sender_whitelist
systemctl restart postfix

Diagnostic Commands

# Check Postfix configuration
postconf -n

# Check Dovecot configuration
doveconf -n

# View mail log
tail -f /var/log/maillog

# Check mail queue
mailq

# Test email delivery
echo "Test" | mail -s "Test Subject" user@example.com

# Check open relay
postconf smtpd_relay_restrictions

# Check DKIM signing
opendkim-testkey -d domain.com -s default -vvv

Additional Resources

• references/postfix.md -- Postfix configuration and mail transfer setup
• references/dovecot.md -- Dovecot IMAP/POP3 setup and tuning
• references/spam-filtering.md -- SpamAssassin and Rspamd configuration
• references/roundcube.md -- Roundcube webmail setup and troubleshooting