[Dovecot] Email filters

Can someone tell me how I can configure Dovecot to use message filters on incoming email? When I now activate my mail account on my mobile phone and Thunderbird (or any other mail client with message filters) is not online, I get a huge pile of email in my INBOX that I have to go thru, while 90% is not that interesting to read as they belong to Spam messages, newsletters etc.

Thanks in advance Jos Chrispijn