[wlug] procmail bounce matching

Hi, I have recently started having lots problems with people spamming with the from address of my domain and the domain catchall getting ~2 - 5k bounces arriving in my mailbox each day. I really don't want to remove the catchall, just get rid of all the random bounces. All my incomming mail is filtered through procmail and I want a good procmail recipe to match on bounces and chuck them away. Unfortunatly I don't seem to be able to find any reliable way to match a message as being a bounce without just lots of from filters detecting the common from styles of the different SMTP servers out there. Any suggestions ? Cheers, Jamie