It appears that Wietse Venema <postfix-users@postfix.org> said: >> BINARYMIME avoids the 33% size increase of base64. If people cared >> about that, since every MTA now supports 8BITMIME it would be easy >> to invent a quoted-unprintable content-transfer-encoding which >> escaped only the few characters that are special in 8BITMIME (CR >> LF NUL and to be on the safe side, 0xff.) That would get you about >> 98% of the way to binary with 2% of the work. > >This would turn binary content into a long line. That works perfectly >with qmail and Postfix (except that the Postfix SMTP client will >need a hint to avoid folding such lines at the 998 octet limit of >RFC 5321).
My quoted-unprintable would turn NUL CR LF \ xFF into \0 \r \n \\ \x. The decoder ignores unescaped CR and LF. Just like with base64, insert an unescaped CR LF after every 998 octets to make the lines the right length. That still would put you within 2% of the size of pure binary. R's, John
