uAdmin

Mail server

ClamAV antivirus on the mail server

Installing ClamAV via the uAdmin wizard, Rspamd integration, RAM requirements, panel management and EICAR testing.

  1. How it works

    ClamAV does not attach directly to Postfix — uAdmin integrates it through the Rspamd antivirus module. Every message passing the milter (port 11332) can be scanned; a virus gets the CLAM_VIRUS symbol. The default action is reject.

  2. RAM requirements

    clamd uses significant RAM (virus signatures). The install step is skipped automatically if the VM has less than ~1.2 GB free memory and less than ~2.8 GB total. For production use a mail VM with at least 2 GB RAM (4 GB ideal). On a smaller VPS you can force installation with UADMIN_MAIL_CLAMAV_FORCE=1 on re-apply.

    Minimum (auto-skip below this):
  MemAvailable < 1200 MB AND MemTotal < 2800 MB

Recommended:
  2 GB+ RAM for mail + rspamd + clamav

Force on 2 GB VPS:
  UADMIN_MAIL_CLAMAV_FORCE=1

  3. Installation (new server)

    The mail wizard automatically runs the «ClamAV antivirus» step after Rspamd installation. Order: Postfix → Dovecot → Rspamd → ClamAV → Apache/Roundcube → Connector.

  4. Existing mail server

    After panel OTA to 1.0.400+: Mail → Server overview → Update connector (0.9.5). Then Mail → Settings → Re-apply: ClamAV antivirus. Check Mail → Rspamd → Overview — the ClamAV card should show installed + enabled.

  5. Panel management

    Mail → Rspamd → Overview: enable/disable scanning, choose action (Reject or Add header only), set max scan size (1–100 MB). Changes write to /etc/rspamd/local.d/antivirus.conf and reload Rspamd.

  6. EICAR test

    Send a test message with the EICAR test string in the body (plain text). Rspamd should mark CLAM_VIRUS and reject the message if action is reject. Do not use production addresses for experiments — use a test mailbox.

    X5O!P%@AP[4\PZX54(P^)7CC)7}-STANDARD-ANTIVIRUS-TEST-FILE!+H*
    Tip

    Service check on mail VM: systemctl status clamav-daemon clamav-freshclam rspamd; cat /etc/rspamd/local.d/antivirus.conf