This is an *EASY* problem to fix, Len.
If there is a problem to be fixed.
If they use RFC-compliant blocking, AOL will send the 5xx response. If the spammer connects again to send the E-mail, AOL instantly blacklists the IP.
So you're saying all is cool with your disaster scenario if AOL sends just one 5xx and then does the IP blocking for all subsequent attempts from a given IP?
At that point, they can silently drop packets from the IP. Much less bandwidth used this way
how so? every blocked MTA will still keep trying all the MX IPs whether they see the single 5xx or not. The 5xx applies to only one msg, so what happens if I have another 499 msgs for AOL and my IP is TCP blocked? How does that initial 5xx change anything for me? I will try to send 499 msgs to AOLs MX IPs and get no response.
and it doesn't hurt the innocent victims at all. Yes, there will still be complaints from legitimate mailservers that are blocked by AOL, but at least they will know that they are being blocked.
The admin will know he is being blocked when none of his server's msgs to AOL are delivered, initial 5xx or not.
If AOL does the dumb blocking to us, I'll happily tell anyone who is listening that all of AOL's mailservers are down.
... happily and dumbly.
It would not be reliable or credible to report that to anybody unless you tried AOL's MXs from other IPs or asked other admins if they could send to AOL. Concluding that all of AOL's MXs are down because you alone can't send to them is ridiculous.
No. No spamware that I've heard of will retry 96 times. This may happen with an open relay, but not with open proxies and direct-to-MX spamware. And that does little to tarpit the spammers -- that's using up about 1.5% of the resources of real tarpitting.
All spammers will keep pounding on AOL's MXs even if they see one 5xx, or 1000 5xx's. That's exactly the punishment AOL is trying to escape. AOL cannot stop the abuse at the SMTP level, so they drop down to the TCP level.
If tarpitting occurs, great, if it doesn't, I'm sure AOL doesn't care. Tarpitting is not the objective, it's only a happy side effect if it occurs.
But every blocked sending MTA will try an AOL IP and wait probably 10's of seconds before timing out. That's pretty effective tarpitting. If they see TCP connection refused, then the tarpitting is ineffective, no big deal.
conclusion: if you want send email to AOL, you better get your DNS and mail server in perfect shape, or else.
That's irrelevant. As long as there is a significant portion of legitimate mailservers being blocked, it needs to be done properly.
So, is there a "significant portion of legitimate mailservers being blocked"?
If not, AOL's TCP blocking, without or without a first 5xx, is not causing anywhere near the nightmare for bandwidth wastage and $$$ lost by business that you are describing.
AOL is wasting terabytes of Internet bandwidth
How do you know and calculate that for all of Internet? This seems like front page tech news, so where else is this AOL disaster been reported? How long has it been going on?
costing small businesses lots of money
How do you know and calculate that? I haven't seen this AOL nightmare discussed on this list or on any of the lists I follow, or in the tech press. How nightmarish can it be?
Len
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