Filter question

Hi

I don't know if this is possible but...

I sometimes receive mail as a 'bcc' with the sender sending the only 'To' to 
themselves. So in Kmail it looks like the sender and receiver are the same. 
How can I filter these to my local folders (they just sit in my main Inbox 
folder) as I have more than just one correspondent who does this?

The only thing I could think of would be a filter with Sender=Receiver but I 
couldn't see how to do that.

Thanks

David