I removed the HEADER_CHECKS I created from the HOWTO as I don't want to confuse.
Here they are for you expert experimenters.
Last piece, and this will be updated as I get more in depth, header_check in the postfix directory should contain these:
Code:
/^Subject: .* / REJECT Spam Header Many Spaces 1
# Chinese, Japanese and Korean
/^Content-Type:.*?charset\s*=\s*�?(Big5|gb2312|euc-cn)�?/ REJECT HDR2100: Unaccepted character set: �$1?
/^Content-Type:.*?charset\s*=\s*�?(euc-kr|iso-2022-kr)�?/ REJECT HDR2110: Unaccepted character set: �$1?
/^Content-Type:.*?charset\s*=\s*�?(iso-2022-\w+|euc-jp|shift_jis)�?/ REJECT HDR2120: Unaccepted character set: �$1?
# Cyrrilic character sets: Russian/Ukrainian
/^Content-Type:.*?charset\s*=\s*�?(koi8-(?:r|u))�?/ REJECT HDR2200: Unaccepted character set: �$1?
/^Content-Type:.*?charset\s*=\s*�?(windows-(?:1250|1251))�?/ REJECT HDR2210: Unaccepted character set: �$1?
I will continue to build the header_check file as time goes on. So stay tuned.