[Exim] string overflowed buffer in pipe command

Hello Exim Experts,

I'm running a pipe transport and getting "**** string overflowed buffer ****". I've played with my command arguments for a few hours and haven't fixed anything yet.

Can anyone give me a hint about what buffer I'm overflowing?

The transport is:

doorman_transport:
driver = pipe
command = DOORMAN_HOME/scripts/doorman.py "TYPE" $reply_address "NAME" $h_subject: RECIPIENT_ID
current_directory = DOORMAN_HOME
home_directory = DOORMAN_HOME
user = DOORMAN_UID
group = DOORMAN_GID


The debug output around there looks like:

direct command after expansion:
argv[0] = /b/local/doorman/scripts/doorman.py
argv[1] = INSIDE-LIST
argv[2] = send2md@???
argv[3] = final@???
argv[4] = test
argv[5] = 58
Writing message to pipe
condition: def:return_path
result: true
expanding: $return_path
result: send2md@???
expanding: MAILER-DAEMON
result: MAILER-DAEMON
skipping: result is not used
expanding: From ${if def:return_path{$return_path}{MAILER-DAEMON}} ${tod_bsdinbox}

result: From send2md@??? Mon Jul 19 16:07:39 2004

writing data block fd=10 size=48 timeout=3600
writing data block fd=10 size=290 timeout=3600
writing data block fd=10 size=1 timeout=3600
set_process_info: 10987 **** string overflowed buffer ****
doorman_transport transport yielded 2
search_tidyup called
close MYSQL connection: localhost/maildance/root
doorman_transport transport returned FAIL for final@???
post-process final@??? (2)
LOG: MAIN
** final@??? R=doorman T=doorman_transport: Child process of doorman_transport transport returned 1 from command: /b/local/doorman/scripts/doorman.py
>>>>>>>>>>>>>>>> deliveries are done >>>>>>>>>>>>>>>>


I don't think my program is running at all because there is nothing in its log.

Any hints will be very much appreciated.

I'm running 4.40 but had the same trouble on 4.34

Thank you,

Marilyn Davis