I have a VPS with about 20 sites on it. I haven't been paying too much attention to the email system to this point, but then I started having lots of trouble with the webmail (takes literally minutes to load each page), so I thought I would check things out.
A few of the busier sites on the server had catch-all addresses set up to put all unrouted mail in the default mailbox, which no one was using (a mistake in retrospect). A few other people have apparently not checked their email in months. In both cases, the mailboxes are full of thousands (sometimes tens of thousands) of messages, 99% of it spam, and the other 1% I don't care about.
Is there any simple way to empty out those mailboxes without having to download all the messages? Most of the mailboxes are the ones that come with each account in cPanel, so I can't just delete the boxes themselves. I've got cPanel/WHM on the server, and shell access if I need it. I'm fairly new to this (never paid much attention to this stuff before) and I have no idea what tools are out there that might be able to help me out.
Anyone have any advice?