Cisco Cisco Email Security Appliance C160 Mode D'Emploi
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Cisco IronPort AsyncOS 7.5 for Email Advanced Configuration Guide
OL-25137-01
Chapter 6 Using Message Filters to Enforce Email Policies
Blank “From:” Filter
Identify blank “From” headers,
This filter can alleviate various forms of blank “from” addresses:
If you also want to drop messages with a blank envelope from, use this filter:
SRBS Filter
SenderBase Reputation filter:
blank_mail_from_stop:
if (recv-listener == "InboundMail" AND header("From") == "^$|<\\s*>") {
drop ();
}
blank_mail_from_stop:
if (recv-listener == "InboundMail" AND (mail-from == "^$|<\\s*>" OR
header ("From") == "^$|<\\s*>"))
{
drop ();
}
note_bad_reps:
if (reputation < -2) {
strip-header ('Subject');
insert-header ('Subject', '***BadRep $Reputation *** $Subject');
}