Lately I've noticed that posts to the lists that I support have
been getting stuck in the spool directory.  Here's some examples
of what I see in the logs repeatedly while those messages are
stuck in the queue.

-> RCPT TO:<[log in to unmask]>
450 <[log in to unmask]>: Recipient address rejected: Domain not found

Its as if a post is held in the spool directory because a recipient
somewhere in the middle of the list is undeliverable.  In order to
clear it up I can either tell my MTA to return a 550 error code
instead of 450 or I can manually edit the .mail file and remove
the offending email address[1].  I'd rather not have to do either
one but by doing either one the rest of the recipients of the stuck
post finally get their copy.

At first I thought it might help to add the following to my go.user
script and restart listserv.

SMTP_FORWARD_1="2*MY.HOST.NAME"

This didn't work as I found several posts from over the past
few days stuck in the spool again this morning.  Is there anyway
to tell listserv to not queue posts itself but rather send the
messages to my MTA and let it take care of them?

Thanks.

-steve

[1] The bad email addresses are also either removed from the lists
or set to not receive posts to keep them from doing the same thing
on the next post.