[Exim] envelope_to_add not working for pipe transport

Hi

As the subject says.

I have a virtual domain aliasfile with:

foo: "|/bin/bar"



my configure file contains the following transport:
address_pipe:
driver = pipe
envelope_to_add
return_output


"Envelope-to: " header is inserted for file transports, but not pipe
transports and I require it for processing of recipient.


Thanks
Gary