--On Thursday, December 09, 2004 01:12 +1100 Craig Sanders <cas@taz.net.au> wrote:
if it's a false positive, the sender will get a bounce from their MTA and they can fix the problem or route around it. IMO, that's far nicer to legit senders than them not knowing that their mail isn't being delivered because it's stuck in their MTA's queue rather than bouncing back to them - the former means it's probably 5 days before they know there is a problem, while the latter gives them instant feedback.
You massively over estimate the intelligence of email users. Far far over-estimate it. When we were doing 5xx returns, about a dozen bounces a day were reported as SPAM to my abuse address. Further more, most people do not understand bounce messages, at all. For us it's far cheaper to let the mailservers deal with it, and delay and bounce later, than involve a human for all the people who just don't get it, but get unlisted before they even READ the bounce.
When a legit user accidentally gets into a black-list their request to get the black-list adjusted can often be processed within the time that their mail server is re-trying the message.similarly, they can resend the message themselves when they know the problem has been fixed, WITHOUT flooding my logs with crap i don't want to see AND they'll have had immediate feedback about the problem with their mail system. everyone wins.
If they ever get the bounce message, increasingly I'm seeing the owrrying trend that bounce messages from MTAs end up as SPAM or just /dev/null-ed.
if it's important, they'll resend it. if the sender doesn't think it's important enough to bother resending, then why should i care?
If the sender even understands that it wasn't sent at all. Many, if not most, don't. Your average @aol.com-er doesn't. For a busines it might be acceeptable, for an ISP doing 5xx is hard to justify, atleast in our case.
Anyway there certainly ARE merits to both sides, and I can and do understand and see your point. I don't like the log chatter but that's easy to deal with compared to our L1 support time when we 5xx. People get stupidly angry sometimes too 'you have no right to bounce my mail!' that's like saying the post office has to deliver all bombs, but logic has nothing to do with most people :)