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Configure Email and DNS (Sysadmin)

The System Admin module (sometimes called "Sysadmin Pro" — separate from the menu category "System Admin") manages host-level settings: SMTP relay (for VM-to-email and notifications), DNS resolvers, time zone, network interfaces, hostname, intrusion detection.

Before You Start

  • Decide which SMTP relay to use (Gmail with app password, Sangoma SMTP, an internal mail server, SendGrid, etc.).
  • For DNS: prefer 1.1.1.1 / 1.0.0.1 (Cloudflare) or 8.8.8.8 / 8.8.4.4 (Google) over carrier defaults.

Steps

Email setup

  1. Go to System Admin → Sysadmin → Email Setup tab.
  2. Pick SMTP Configuration:
    • No relay — Postfix delivers directly. Often blocked by recipient mail servers (no SPF/DKIM). Don't use for production.
    • SMTP Relay — recommended. Fill in:
      • Server — e.g. smtp.gmail.com:587, smtp.sendgrid.net:587.
      • Username — sending email address (e.g. notifications@example.com).
      • Password — app password / API key.
      • Use TLS — Yes for port 587.
  3. From Address — what From: header to set on outbound emails. Should match a sending address allowed by the relay.
  4. Click Submit.
  5. Test:
echo "test message" | mail -s "Test from UnifiedBX" you@example.com
tail -f /var/log/maillog

DNS setup

  1. Sysadmin → Network Settings tab.
  2. DNS section:
    • DNS 1 — 1.1.1.1.
    • DNS 2 — 8.8.8.8.
  3. Click Submit. Tests resolution immediately.

Time zone & NTP

  1. Sysadmin → Time Zone tab.
  2. Pick zone (America/New_York for ET).
  3. NTP server — pool.ntp.org is the default, fine for most.
  4. Submit. System time syncs.

Hostname

  1. Sysadmin → Hostname tab.
  2. Set the FQDN (e.g. pbx.client.com). Should match DNS records and any TLS certs.
  3. Submit. System will need a reload.

Intrusion Detection (Fail2ban)

  1. Sysadmin → Intrusion Detection tab.
  2. Toggle on. Default rules block SIP/SSH/HTTP brute force.
  3. Whitelist — your management IPs (CRITICAL — don't lock yourself out).
  4. Ban duration — 1 hour is reasonable.
  5. Submit.

Verify

  • Email: send a test VM, confirm email arrives.
  • DNS: dig google.com from the host.
  • Time: date shows correct local time.
  • Hostname: hostname -f shows full FQDN.

Common Issues

  • Test email "permission denied." Postfix can't write spool. chown -R postfix:postfix /var/spool/postfix/ and restart Postfix.
  • Email shows in /var/log/maillog as "deferred." Relay rejecting auth. Check username/password; for Gmail, must be an "App Password," not the account password (and 2FA must be on).
  • DNS resolution intermittently fails. Both DNS servers down or slow. Add a third in /etc/resolv.conf manually (Sysadmin only stores 2).
  • Fail2ban blocks legit users. Add their IP to whitelist. Or check /var/log/fail2ban.log for what triggered.
  • Hostname change breaks Apache. Cert SAN no longer matches. Regenerate Let's Encrypt cert with new hostname.