I’m getting a fair amount of Spam where the To, From, and Subject lines have been unnecessarily encoded using QP even though they’re all ASCII.
This is a violation of RFC-2822 and Postel’s Law, and a characteristic of Spam more often than Ham (where legitimate MUA’s attempt to use the least complex encoding suitable in the interests of interoperability). header __L_SUBJECT_QP_ENCODED Subject:raw =~ /^ ?=\?(utf|UTF)-8\?Q\?/ header __L_SUBJECT_ASCII_ONLY Subject =~ /^[[:print:]]*$/a header __L_FROM_QP_ENCODED From:raw =~ /^ ?=\?(utf|UTF)-8\?Q\?/ header __L_FROM_ASCII_ONLY From =~ /^[[:print:]]*$/a header __L_TO_QP_ENCODED To:raw =~ /^ ?=\?(utf|UTF)-8\?Q\?/ header __L_TO_ASCII_ONLY To =~ /^[[:print:]]*$/a meta L_UNNECESSARY_QUOTING (__L_SUBJECT_QP_ENCODED && __L_SUBJECT_ASCII_ONLY || __L_FROM_QP_ENCODED && __L_FROM_ASCII_ONLY || __L_TO_QP_ENCODED && __L_TO_ASCII_ONLY) describe L_UNNECESSARY_QUOTING Header lines have unnecessary Quoted-Printable encoding score L_UNNECESSARY_QUOTING 20.0 Anyone want to sandbox this and see how it performs on a larger sample size? We’ve been using it but it gets FP’s with GreenArrow Studio and Mailchimp, so we’ve had to whitelist those campaign mailers… they’ve been made aware of the issue. Thanks
