Here's a little bit of a modification to the traditional way to use
ClamAV to give more meaningful rejection messages
warn malware = */defer_ok
set acl_c_clam_message = ${lc:$malware_name}
drop condition = ${if
match{$acl_c_clam_message}{trojan|worm}{true}{false}}
message = CLAMAV - Contains a VIRUS ($malware_name)
drop condition = ${if match{$acl_c_clam_message}{spam}{true}{false}}
message = CLAMAV - Message is Spam ($malware_name)
drop condition = ${if match{$acl_c_clam_message}{images}{true}{false}}
message = CLAMAV - Contains Image Spam ($malware_name)
drop condition = ${if match{$acl_c_clam_message}{phishing}{true}{false}}
message = CLAMAV - Message is a PHISHING SCAM ($malware_name)
discard condition = ${if
match{$acl_c_clam_message}{bounceback|blowback}{true}{false}}
logwrite = DISCARDED - CLAMAV - bounceback - ($malware_name) -
$acl_c_information
drop condition = ${if def:acl_c_clam_message}
message = CLAMAV - Misc Spam ($malware_name)