Lost in Reception

Terry writes a reasoned post on the consequence of the use by users of “This is Spam” buttons for no-longer-wanted newsletters, but then makes on odd assertion:

The one drawback of this feature is that the sender is blissfully unaware that their messages are not getting through to the end user.  However, that’s a topic to be dealt with by the email-deliverability folks, I’m in the business of impeding mail flow!

I have a longer post coming on deciding-at-SMTP-receipt time what to do with a message. Some of the arguments are finely balanced but this one is a slam dunk: if the recipient has indicated that they don’t wish to receive messages from a specified sender and that sender sends to that recipient again, then the message should be refused at RCPT TO (i.e. before the message even crosses the wire). This makes clear to the sender that this address is not to be sent to again and does so in a way which reduces resource consumption in the anti-spam system; it’s an actual free lunch!

Oh, and Terry, if you’re really in the business of impeding mail flow, you could save yourself a lot of trouble by simply turning off your servers :-) I’d suggest that you’re actually in the business of facilitating the flow of legitimate mail and that impeding the flow of abusive mail is merely a means to that end.