I had the same problem with maildrop and notmuch. I figured out that exim is adding the From_ line, but it can be disabled. Something similar is probably true of other MTAs.
The default value for message_prefix in the exim pipe transport looks like this: message_prefix = \ From ${if def:return_path{$return_path}{MAILER-DAEMON}}\ ${tod_bsdinbox}\n You can disable it by adding 'message_prefix = ' to your maildrop_pipe transport, this is mine: maildrop_pipe: debug_print = "T: maildrop_pipe for $local_part@$domain" driver = pipe path = "/bin:/usr/bin:/usr/local/bin" command = "/usr/bin/maildrop" message_prefix = message_suffix = return_path_add delivery_date_add envelope_to_add I'm probably going to file a separate bug against exim requesting that the Debian exim config for maildrop_pipe doesn't add a From_ line. -- Edward. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org