Those of us who have been here "awhile" (since 1998 for me) know that there is no "start coming down on users who do that" needed that is not already being done. The quickest way I know of to get "booted" off DH, with no refund and way to even get at your files once you are "shut down" is to try to pump spam from a DH server. You won't get far, believe me. But exploitable scripts do get loaded by users onto DH servers, and every now and then one of them runs amok, or a user tries to send spam, and while he gets caught and booted, the damage is done in the minds of the "fascist" spam managers at some of these other companies. This is one risk of living on a shared server, and using dynamic IP addresses. It was our choice: we could have set up our own boxes, arranged our own bandwidth, managed our own IP's, etc, or have someone else do all that by spending "big money".
Now that's interesting, as I have not heard DH put it that way before, but (as you know from my previous post) it is not the least bit surprising. Do you think they, or anyone else, can do anything to change AOL? or Hotmail? And it is not just these guys (though they have been the problem of late), Earthlink, has done similar, and a good googling will reveal that DH is not alone in this: whole blocks of dynamic IP addresses form broadband providers have been subjected to this kind of "we won't process/deliver any mail that comes from your corner of the net" attitude.
I agree with you that we will have to find some way of dealing with it, maybe contract with an email provider for that service (though they will, given time, have the same problem). As for how long DH customers will "put up with it", my guess would be no longer than they have to - but that presumes they are able to find another provider that doesn't have this same problem with AOL/Hotmail/etc.
It could be a lot worse, as not all of DH servers are presently "blocked", and the "blocked ones" will, at some point be "unblocked", and others that are fine now will get blocked, and the cycle will continue until AOL (which is bleeding customers so fast it makes your head spin) customers start screaming at AOL, "Why can't I get my mail?"
Me too, and it is not that I am not sympathetic to this issue as it affects us all. I, however, have been here a long time, and have seen these AOL/Hotmail/other "issues" rear their ugly heads, get dealt with, and go away for long period of time before the "rear their ugly heads again". The "big guys" have the same problem; almost any online store you buy from warns you of this potential problem.
I wish I had a better answer, but I don't. I do know that, until the net evolves to the next level of email, or somehow we control the @#&% spammers, this is going to be an ongoing problem for all of us on shared hosting everywhere. Any webhost who is not having the problem now, will have the problem at some point in time.
I believe that DH is one of the Best of the Best, and they will do all they can to make it better - but you can't make someone else do what you want just by wishing it so. I have dealt with AOL for years, and I wouldn't wish that on people I don't even like!