"dynamic" number of smtpd processes ?

Hi,

after what has happened today (Mydoom & Mimail.R viruses),
i've seen that one of our mailgateways had some "load" problems.

we are using postfix + amavisd-new + spamassassin.

what happened is that the system was unable to process emails
as fast as it received them, so the mailqueue growed
exponentially
(there were like 6000 mails waiting to be processed)

there were also always about 10-15 smtpd processes on the
system (incoming mails)

i then asked myself if it would be possible to have postfix
automatically reduce the maximum allowed number of smtpd
processes (and therefore the maximum number of inbound
smtp sessions) maybe in function of the load-average

of course, i could write a script which tunes the number
of smtp processes and does a "postfix reload" (if required)
every 10 minutes


thanks