sendmail discard subjects

[Remco Barendse]

I am using mailscanner rules to discard emails that have a certain 
subject.

This works great for some viruses and read and not read receipt messages 
that are extremely annoying.

Any read / not read messages usually have subject that looks like Read: 
blabla subject
This is only the case for replies to mails that are in the regular 
character set. These rules do not catch mails that reply to mails that 
were in a different character set.

If I look in pine the mail subject looks normal but when I look in the 
qf/df pairs the subject looks like this:
H??Subject: =?iso-8859-1?Q?Read=3A_Angaben_f=FCr_Tarragona

I tried the following in my subjects file:
read:
=?iso-8859-1?Q?Read=3A_
not.read:
?iso-8859-1?Q?not_read
gelezen:
niet.gelezen:
leído:
no.leído:
lida:
lidas:

but the strange character set ones still get through and the 2 lines that 
include the iso char set do not seem to work.

need I do anything special so sendmail will recognize these other messages 
as well??