ietf-822
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Re: CRs in messages

2001-05-22 12:48:37

> Is it our MTA which is incorrect by interpreting <CR>.<CR> as the same as
> <CR><LF>.<CR><LF>
> or is it the sending MTA/MUA which is incorrect by creating a message with
> <CR>s in it and then not padding the '.'. (Surely if it really wants <CR>
> characters rather than <CR><LF> line terminators, it should use
> Quoted-Printable or Base64 encoding, not just put them in there as ASCII
> 0x0d characters)

your MTA is making a too-liberal application of the "be liberal in what you
accept" principle.  unfortunately there used to be a lot of MTAs (mostly
misconfigured sendmails) that would send <LF>.<LF> (not sure about <CR>.<CR>)
rather than <CR><LF>.<CR><LF>, to terminate the message.  many MTAs adapted
by accepting any of  <CR> <LF> or <CR><LF> as line terminators.

the sending MUA probably shouldn't be putting bare <CR>s in the message either.
however, this is perfectly legal in RFC 822.

Thanks to everyone for the feedback.

The MTA is one we wrote ourselves, so we'll add an option to it to either accept ONLY CRLF as line terminators in messages (the new default) or accept any combination of LF, CR, CRLF (or even LFCR which we've seen in one instance from an MUA a couple of years ago..)

We may make this a bit smarter in the future. One thing we've spotted in this case is that the message header is all formatted correctly, but the message body has bare CRs in it, so we may say that if the header is correct then we'll assume the rest of the message should be, but if the header uses just CRs or just LFs then we'll assume the rest of the message is the same as well.

Thanks

Paul


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