working and documented script

disclaimerfilter.py

@@ -2,7 +2,17 @@
 """
 Postfix filter for adding a disclaimer to selected email.
 
-Emails are 
+Emails are either passed through to sendmail/postfix or - if matching a rule - piped through altermime first.
+See https://dukun.de/xox/altermime/postfix-altermime-howto-2.html for more details
+
+Place script in Postfix folder, make sure disclaimer files are in the right place and adapt Postfix config via master.cf:
+> […]
+> submissions inet  n       -       n       -       -       smtpd
+>    -o content_filter=disclaimerfilter
+> […]
+> # disclaimer filter - add a disclaimer to certain emails going out as list
+> disclaimerfilter     unix    -       n       n       -       -       pipe
+>  flags=Rq user=filter argv=/etc/postfix/disclaimerfilter.py -f ${sender} -- ${recipient}
 
 License: GPLv3
 Author: Georg Schlisio
@@ -53,9 +63,6 @@ rules = [
         ["chor@greifswalder-domchor.de", "/etc/postfix/mailinglists/disclaimers/domchordisclaimer"]
         ]
 
-# DEBUGGING CASE - don't use in production! overwrites above 
-rules = [["abmelden@augustiner-kantorei.de", "augustinerdisclaimer"]]
-
 # read input and find recipient
 mail = "".join(sys.stdin.readlines())
 recipient = email.parser.HeaderParser().parsestr(mail)["To"]
@@ -83,5 +90,5 @@ for rule, disclaimer in rules:
         # only first matching disclaimer!
         break
 
-sendmailprocess = subprocess.Popen(["/usr/bin/sendmail"] + sys.argv[1:], stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+sendmailprocess = subprocess.Popen(["/usr/bin/sendmail", "-G", "-i"] + sys.argv[1:], stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
 sendmailprocess.communicate(input=mail.encode('utf-8'))