Mail headers will indicate scanners are working: scanners: regex: 1.4.0 attach: 1.4.0 clamav: 0.103.2/m:62/d:26347 spam: 3.4.6 rspam: 3.2-1 dspam: 3.10.2 (agent/library) To troubleshoot simscan, clamav, spamc, rspamd, or dspam add 'SIMSCAN_DEBUG="5"' to tcp.smtp, reload cbd (qmailctl cdb) and watch output of smtp log. You should see something like the following: 2020-10-15 13:14:54.487439500 simscan: runned_scanners is attach: 1.4.0 clamav: 0.102.4/m:59/d:25957 2020-10-15 13:14:54.487447500 simscan: found 0.102.4/m:59/d:25957 2020-10-15 13:14:54.487447500 simscan: normal clamdscan return code: 0 2020-10-15 23:20:18.803403500 simscan: calling spamc 2020-10-15 23:20:18.803412500 simscan: calling /usr/bin/spamc spamc 2020-10-15 23:20:20.417465500 simscan: cdb looking up version spam 2020-10-15 23:20:20.417467500 simscan: runned_scanners is regex: 1.4.0 attach: 1.4.0 clamav: 0.103.2/m:62/d:26347 spam: 3.4.6 rspam: 3.2-1 dspam: 3.10.2 (agent/library) 2020-10-15 23:20:20.417468500 simscan: found 3.4.2 2020-10-15 23:20:20.417468500 simscan:[4629]:CLEAN (0.30/12.00):1.9820s