dhananjay <dhananjay(_at_)zlemail(_dot_)com> wrote:
Now, consider a scenario where a mail client (supporting 8bit) sends
an email with a binary-converted-to-8bit attachment
Also, could you please point out some mail clients dealing 8bit.
Do you understand that currently there is no binary-to-8bit
conversion registered in the transfer-encoding registry
(http://www.iana.org/assignments/transfer-encodings)? There is a draft
for deflate-8bit (draft-freed-mime-newenc-00), but I would be surprised
if any mail clients implemented it already, since it's likely to change.
Currently, the only standard way to get an 8bit message body is for the
body to originate as 8bit (for example, plain text in almost any charset
except ASCII); there is no standard conversion from binary to 8bit.
I would like to know flow for following 2 cases :
1. 8bit MTA sending mail to 7bit MTA with Subject line in header having 8bit
characters.
RFC2822 says "A field body may be composed of any US-ASCII characters,
except for CR and LF." So, such situation is quite possible.
In this case dealing with 7bit MTA becomes very tough, as sending 8bit
MTA will have to parse each possible header field body, and do necessary
encoding to QP, and poor 8bit MTA has no way out.
2. 8bit MTA sending mail to 7bit MTA with Message body text having 8bit
characters.
In this case, 8bit MTA will have to encode message body text into
base64/QP and send it as attachment to original header of message. So, user
sees message body text as attachment.
is such change in mail structure allowed ?
Regards,
Dhananjay.