How to debug custom delivery options ?

Hi

Release 12.2.6

I'm trying to define and use a custom delivery option. Basically i just want to zip the output file. I've defined the Custom with the following command line:

/usr/bin/gzip {file}

However, when i test it, the concurrent program doesn't end with error but the output file is not compressed either... Is anyone knows how i can debug this feature ? what log can i check ? OPP ?

An other question about the delivery options: could we use two at the same time for the same request ID (for instance the Email+Custom) ?

Thanks for your help

Christophe