I'm running RedHat 7.3 with qmail and spam/virus filtering done via
spamassassin, which is invoked by procmail on a per user basis. Every
other day or so, the mailserver seems to burp and really slow down
performing local mail delivery. When I monitor the box with "procinfo
-fdbn1" I'm seeing almost no cpu or disk usage, yet when I do a "ps
-ajx", I'm seeing several procmail processes just sitting there in a
sleep state.

15495 15498 3717 3383 ? -1 S 1112 0:00 preline
/usr/bin/procmail -m ./.procmailrc
15498 15499 3717 3383 ? -1 S 1112 0:00
/usr/bin/procmail -m ./.procmailrc
3722 15575 3717 3383 ? -1 S 1112 0:00 [qmail-local]
15575 15579 3717 3383 ? -1 S 1112 0:00 preline
/usr/bin/procmail -m ./.procmailrc
15579 15580 3717 3383 ? -1 S 1112 0:00
/usr/bin/procmail -m ./.procmailrc
3722 15734 3717 3383 ? -1 S 1112 0:00 [qmail-local]
15734 15738 3717 3383 ? -1 S 1112 0:00 preline
/usr/bin/procmail -m ./.procmailrc
15738 15739 3717 3383 ? -1 S 1112 0:00
/usr/bin/procmail -m ./.procmailrc
3722 15879 3717 3383 ? -1 S 1112 0:00 [qmail-local]
15879 15881 3717 3383 ? -1 S 1112 0:00 preline
/usr/bin/procmail -m ./.procmailrc
15881 15882 3717 3383 ? -1 S 1112 0:00
/usr/bin/procmail -m ./.procmailrc
3722 16266 3717 3383 ? -1 S 1112 0:00 [qmail-local]
16266 16268 3717 3383 ? -1 S 1112 0:00 preline
/usr/bin/procmail -m ./.procmailrc
16268 16269 3717 3383 ? -1 S 1112 0:00
/usr/bin/procmail -m ./.procmailrc
3722 16322 3717 3383 ? -1 S 1112 0:00 [qmail-local]
16322 16324 3717 3383 ? -1 S 1112 0:00 preline
/usr/bin/procmail -m ./.procmailrc
16324 16325 3717 3383 ? -1 S 1112 0:00
/usr/bin/procmail -m ./.procmailrc

When I use "top" and watch the processes, I see spamassassin processes
being invoked, but they quickly finish, so I doubt spamassassin is the
problem. All the users have simple procmail confs with nothing more
than the following:

:0c
$HOME/MAILBOX/mail.bak

# SpamAssassin
:0fw: spamassassin.lock
* < 250000
| /usr/bin/spamassassin -P


Even the sorting of mail tagged with spam headers is done in their
outlook clients, so I see no reason for local delivery to take so
long. I do a /var/qmail/bin/qmail-qread and see all the messages
sitting in the queue and tons of them have local destinations, but
qmail seems to be either limiting the amount of local deliveries it
will make while it waits for procmail to finish or it's just not
sending them to qmail-local. Can anyone advise me on how to find the
bottleneck? Any help would be greatly appreciated; thank you.