Question regarding 8BITMIME / BINARYMIME


I have a question regarding 8BITMIME.

I know Postfix supports 8BITMIME and does not support BINARYMIME, but I am wondering why both 8BITMIME and BINARYMIME are ESMTP extensions. It would appear that 8BITMIME solves the same problem as BINARYMIME (allow 8-bit encoding of MIME), so why wasn’t BINARYMIME made obsolete in the RFC’s ?

Also - because 8BITMIME seems to solve the problem without CHUNKING, is that why Postfix supports it over BINARYMIME ?


- J


Re: Question regarding 8BITMIME / BINARYMIME

By Bill Cole at 03/13/2018 - 01:14

They don't quite solve the same problem. See
<a href="" title=""></a> and note that the ability
to transport any 8-bit character as message content does not include the
ability to transport any arbitrary stream of bits. 8BITMIME is really
designed to avoid the need to use Base64 or Quoted-Printable for text
email messages using extended 8-bit charsets or UTF-8.

I can't give a definitive answer to that, but it seems to me that the
added complexity of BINARYMIME+CHUNKING implementation and support is
too high a cost for what it provides over 8BITMIME.