Hope this helps,
ABSOLUTELY! I wrote a talk list program in Perl that I use on a couple
of my domains. I use procmail to read TO, and then forward the letter to
the program if the letter is addressed to one of the talk lists. I've had
trouble with letters dying if the talk list program is still dealing with
a previous letter while another tries to access the program. If I'm reading
your letter correctly if I have :0: any subsequent letters to the list
program will remain in a holding pattern until the lock is released.
Thanks!
Glen