[Exim] return_path and appendfile transport doesn't work

Hello,

[appendfile transport]
TV> using the 'return_path' statement within the transport
TV> specification, this only affects the "Return-Path:" header if
TV> 'return_path_add' is set to true. The real envelope sender ("MAIL
TV> FROM") is never changed.

sorry, I think my writing was a little bit fuzzy here, so let me point it
out again:

The behaviour I am wondering about is that the envelope sender is not
changed at all when using 'return_path' within the appendfile transport.

Greetings, Thomas