Posts Tagged by Procmail

I blogged a while ago about using FuzzyOcr for detecting image spam. My FuzzyOcr isn’t working and at the moment I haven’t got time to fix it, so I wrote a procmail recipe to solve the problem instead:

# test if body contains gif, html, etc, and get procmail score
:0 Bc
* 3.5^0 Content-Type: image/gif
* 2^0 Content-Type: text/html
/dev/null
SCORE_PM=$=

# pull out SA score and required; if 2 scores > SA req'd, ISGT = 1 (true)
SCORE_SA=`formail -c -xX-Spam-Status: | awk '{print $2}' | awk -F= '{print $2}'`
REQD_SA=`formail -c -xX-Spam-Status: | awk '{print $3}' | awk -F= '{print $2}'`
ISGT=`echo "${SCORE_SA} + ${SCORE_PM} > ${REQD_SA}" | bc -l`

# test if ISGT = 1, if so, spam prob
:0 :
* ISGT ?? ^^1^^
.y_spam_probable/

Good procmail sites

• Timo’s procmail tips
• ii.com – procmail quickstart
• procmail tips
• Halcyon guide
• Partmaps procmail FAQ
• Stimpy’s formail tutorial

Procmail commands can consist of…

• a statement

 FOO=`formail ... | sed ...`

• a recipe

A recipe consists of three parts…

• a colon line
• zero or more condition lines
• an action section

 :0
 email_folder/

 :0
 * From: ...
 email_folder/

An action is one of…

• a folder

 email_folder
 email_folder/

• a forward

 !foo@bar

• a pipe (with :0 fwh or :0 fwb colon flags)

 | formail -I ...

• a curly brace

 {

Curly Braces

A curly brace starts a nesting block ie a recipe can be:

• a colon line, zero or more conditions, and curly brackets

 :0
 {
     ...
 }

 :0
 * From: ...
 {
     ...
 }

Inside curly brackets there must be one or more recipes.

How to do if-else

Do if-else using the E colon line flag

 :0
 {
     :0
     * ^From: ...
     # deliver to default destination (inbox)
     ${DEFAULT}
 }
 :0E
 {
     # else
     ...
 }