[imp] meaning of missing MIME charset (was: Broken umlauts)

[Otto Stolz]

Alexander Skwar wrote:

> Content-Type: text/plain
> Content-Transfer-Encoding: 8bit
> 
> The Content-Type is missing the charset which is to be used, and thus
> mutt (wrongly??) choses us-ascii to display the message.

Rightly so.

Quote from RFC 2045 <http://sunsite.dk/RFC/rfc/rfc2045.html>:

5.2.  Content-Type Defaults

    Default RFC 822 messages without a MIME Content-Type header are taken
    by this protocol to be plain text in the US-ASCII character set,
    which can be explicitly specified as:

      Content-type: text/plain; charset=us-ascii

    This default is assumed if no Content-Type header field is specified.
    It is also recommend that this default be assumed when a
    syntactically invalid Content-Type header field is encountered. In
    the presence of a MIME-Version header field and the absence of any
    Content-Type header field, a receiving User Agent can also assume
    that plain US-ASCII text was the sender's intent.  Plain US-ASCII
    text may still be assumed in the absence of a MIME-Version or the
    presence of an syntactically invalid Content-Type header field, but
    the sender's intent might have been otherwise.

Best wishes,
   Otto Stolz