Bug - Mime-Version header do not follow RFC 2045



  • The rspamd software is giving all emails from Kopano an extra 0.5 points because mime-version is written in the wrong way.

    Kopano is writing

    Mime-Version: 1.0
    

    RFC 2045 specifies it should be written

    MIME-Version: 1.0
    

    RFC 2045
    Kopano Core v8.7.80
    WebApp 3.5.1.2091+1151.1



  • In my understanding of RFC 2045 which refers to RFC 822, mime-headers are case-insensitive
    Section 3.4.7. CASE INDEPENDENCE.
    Thus, I wouldn’t classify the behaviour a bug.

    “Be conservative in what you do, be liberal in what you accept from others”.

    Probably, the above postulation is a spam-filter-specific optimisation-dilemma.

    ++umgfoin.



  • Thanks for the update about RFC 822. Is seems it has been superseded by RFC 2822.

    In RFC 2822 is says that case-insensitive should only be applied if the value is enclosed in quotation marks. Rest should be case-sensitive.



  • @Blinkiz said in Bug - Mime-Version header do not follow RFC 2045:

    Thanks for the update about RFC 822. Is seems it has been superseded by RFC 2822.

    Yes, you’re right.

    In RFC 2822 is says that case-insensitive should only be applied if the value is enclosed in quotation marks. Rest should be case-sensitive.

    Hello Blinkiz,
    doesn’t this refer specifically to the notation of a sgl. character?

    The syntax definition links to ABNF/ RFC 2234, saying ABNF strings are case-insensitive and ABNF rules are case-insensitive .

    Further on:

                    To specify a rule which IS case SENSITIVE,
                       specify the characters individually.
    
       For example:
    
            rulename    =  %d97 %d98 %d99
    
       or
    
            rulename    =  %d97.98.99
    
       will match only the string which comprises only lowercased
       characters, abc.
    

    ++umgfoin



  • This is outside my knowledge @umgfoin. :-)
    Am just a user trying to make Kopano as good as possible.


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