replying to emails uses default address

is there any way to configure kmail such that when i select 'reply to' the 
address that the the original email was sent to is used as the 'from' address?  
i do not wish to have to make a new identity for every single spam catcher 
address i make with my domain names but i do need to be able to respond to 
some emails sent to these addresses and i'm often caught out by not noticing 
that the reply has my default identity filled in as the 'from' rather that than 
the address the original was sent to!

bascule