Auto-remove Spam Mail from Yahoo Account

After the outbreak of SoBig, my Yahoo! account has been flooding with spam mails.
Since this is a free account, virus protection is very limited.
Although Yahoo! puts spams to Trash automatically, my account is always out of space
because it infrequently purges the Trash. So these few weeks I need to go to the webmail
interface and manually click the empty Trash link to remove them.
But as you may know, the disk space eats up automatically in just half an hour
because new spams come in. This makes my Yahoo! account stalled a while.

So I was thinking an idea of automatic empty Trash using a script, and may be
a nice perl script should do since it can incorporate with HTTP message handling and even
HTTPS connection. I google'd the web and I first found a utility called
YahooPops!. Reading this in details
I found it was only good for POP3 and SMTP access to Yahoo! mailbox, but not quite suitable
at server end (I only need purging). However, follow one of the links from YahooPops!,
it led me to fetchyahoo.
This perl script has all features I need.

I downloaded it and tried with the following commands:

fetchyahoo.pl 
--username=punkytse --password=xxxxxx \
--statusonly --emptytrashbefore \
--spoolfile=/dev/null > /dev/null

"--emptytrashbefore" is the main flag to tell fetchyahoo to delete mails in trash. There
is another "--emptytrashafter" flag that also does the same thing, but the different is
it will empty the trash after accessing Inbox. Since I only need empty trash, these two
flags make no difference to me.
"--statusonly" flag is also important so that your Inbox mails will not be downloaded
or deleted. As I still prefer Yahoo! webmail interface to access my mails, I am not going
to configure it to fetch mails to my local mail spool so that they can be accessed
from punknix using IMAP or POP3 (of course it can).

Side issues. Although I noted that there is a pre-built package in Debian testing, I still use the
"stock" version from fetchyahoo site. This is because the testing package has a lot
dependencies to perl and perl modules that requires me to upgrade those to testing distribution (perl 5.8!).
I don't want to mess up my working system. Moreover, I also tried downloading source and building
it from Debian, but there are some errors. Anyway, as the "stock" version works, I am better off now. At last, I configured a cron job to run it every ten minutes so it
does all the magic to clean up the spams for me.