[Exim] Transport filtering

Hi,

in my mind the documentation about transport filtering has some caveats.

- doc says that filter gets its STDIN before SMTP-processing, like turning '\n' to '\r\n'

I doesn't mention, what is the input. Is it _always_ with '\n' when in Unix or is it _always_ '\r\n' or is it in form as the message was queued so I need to prepare for both line termination?

- about output, what happens to STDERR? Nothing special or going to exim log? Probably nothing special. I ask this because if I want to log something from filter to exim log.

- and finally exit code, can I on purpose cause bounce message by setting exit-code to a non-zero?

Best regards, Jori