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questions on QP, non-text attachments and munpack

1996-02-08 07:05:25
I have a mailer that encodes non-text attachments using either b64 or QP
depending on which would produce the smaller output. This is particularly
useful dealing with almost-text attachments, such as some EDI streams, which
are MOSTLy ascii text but either have extremely long lines or a small number
of binary characters. Encoding these attachments with QP gives a much
smaller increase in size over what would be produced by using b64.

We recently ran into a problem where a customer received a MIME mail
message with such a QP encoded attachment. This customer was using munpack
to extract the attachments.

Now, munpack is a great tool. However, it does one thing that messed up the
attachment for our customer. In the process of decoding the attachment, it
makes the assumption that QP is only being used in text attachments and
STRIPS all CR characters, evidently trying to merge the UNIX CRLF->NL
conversion into the same pass. Unfortunately, this messed up the customer's
software considerably when it tried to use the reconstructed attachment.

Now for the questions:

    o   Is my mailer correct in believing that it should be able to use QP
        for non-text attachments? After all, QP IS supposed to just be an

    o   Is munpack wrong in stripping CR's when dealing with non-text

                                        Tony Hansen