Unsubscribing stupidity

Don't you love it when you get some e-mail from a company you contacted once for some reason and now you want to unsubscribe from receiving further messages -- and this is not just an automatic process through some link? Typically you would have to tell them which e-mail address you want to use to unsubscribe. In my case, I have numerous e-mail addresses forwarded through various domains to my main address, so I have no way of knowing which one it is. This is STUPID!