On Sat, Jun 28, 2008 at 01:56:53PM +0200, Phil Regnauld wrote:
Rich Kulawiec (rsk) writes:
Best practice is refuse all mail that comes from any host lacking rDNS, since that host doesn't meet the minimum requirements for a mail server.
No, that's utterly stupid. You're excluding countries which have poor infrastructure or clueless ISPs (usually legacy telco operators) who can't be bothered to administrate IN-ADDR.ARPA delegations for their customers.
I don't see a problem with not accepting mail from clueless ISPs or their customers. The requirement for rDNS has been around for decades. Anyone who's not aware of it has no business running a mail server.
Millions of botnet PCs have valid reverses.
Yes, I'm well aware of this, especially since I was AFAIK one of the first people to document the use of botnet PCs to send spam. And of course That's why this particular measure doesn't work for them, but other best practices do, e.g., rejecting mail from known-dynamic/generic IP space or known-dynamic/generic namespace unless it's your own customer or is being submitted with authentication non-port 25
Yes, some of these also impact non-spamming but broken mail servers, however, this is usually the only way to get the attention of their operators and persuade them to effect repairs.
You're kidding, right ? They don't give a rat's ass.
Then they should not be troubled that their mail is being rejected.
Locally, .name, .info and .tv are permanently blacklisted, and I recommend this to others: they're all heavily spammer-infested. .biz is not blacklisted at the moment, largely because it's been so badly ravaged that spammers *appear* to be abandoning it.
"Bomb the bridge, salt the earth" approach ?
I'm not the one of the people who thought .info was a good idea (what, domains in other TLDs don't provide "information"?) I'm not the one who decided to sell domains in that TLD to spammers by the tens of thousands, thus effectively devaluing it for everyone else. I'm not the one responsible for failure to enforce any meaningful requirements on registrars to control abuse by their customers. And so on. I suggest laying blame on the people who are responsible for the current state of affairs, not on the recipients of abuse. ---Rsk