Flooded in bounce spam today

It seems spammers have a lot of spare time today.

I received more than 600 spam messages during the last 2 days:

% cut -c 1-78 spam.txt
;-*- coding: utf-8-unix -*-
; List of bounce spam subjects for <October 12-14 2008>

E. 2008-10-12 [ 375: Smart Technical Solu] Νέες Τεχνολογίες: Θερμομόνωση, Δάπε
E. 2008-10-12 [  21: luckymailnl@libero.i] RE: RESPOND UPON RECEIPT
E. 2008-10-12 [  21: luckymailnl@libero.i] RE: RESPOND UPON RECEIPT
:
: 593 messages snipped
:
E. 2008-10-14 [  67: Mail Delivery System] Undelivered Mail Returned to Sender
E. 2008-10-14 [  61: postmaster@anglerboa] Delivery Status Notification (Failu
E. 2008-10-14 [  63: postmaster@swisspost] Benachrichtung zum =?unicode-1-1-ut
E. 2008-10-14 [ 151: <postmaster@elderind] Undeliverable: You have received
E. 2008-10-14 [  75: Mail Delivery System] Undelivered Mail Returned to Sender
E. 2008-10-14 [  74: Mail Delivery System] Undelivered Mail Returned to Sender

More than 90% of them are bounce spam.

Most of them were tagged by Spamassassin, and automatically filed to my “nnml:mail.junk” folder by Gnus. But there is still a fair amount of spam that gets through :-/