palegray.net writes:
"As an employee of a well-known VPS provider, I've been observing another employee's efforts to deal with irresponsible behavior on the part of SORBS, a well-known blacklist provider. Although their mission of providing a resource that system administrators can use to gauge the likelihood of spam originating from a particular IP or netblock is admirable, we've encountered consistent issues related to their assertions with a newly assigned block from ARIN. Jed puts it best:
We recently received a large allocation of IP addresses from ARIN and, to our chagrin, the block is listed on SORBS's list as dynamic IP space — a whole /20 worth of addresses. It has been listed since April and we received it in May. What this means is that to incoming mail servers, all of our customers in this block appear like home customers with a cable or DSL connection (who should not be sending mail).
Obviously, as a hosting company we assign a static to each VPS we provision. Our IP allocations are is in no way dynamic; customers may request an IP address change, but we don't receive many such requests. We always ask for justification, and the requests we approve are typically performed on a "one time only" basis. Jed continues:
I approached SORBS about the issue via their automatic contact system. It has been nearly two weeks since their "bot" replied to me and informed me that most of the block was not eligible for delisting due to the naming convention in our reverse DNS PTRs. We use:
liXXX-YYY.members.linode.com
What's wrong with that? It "looks" dynamic, they say.
Despite our attempts to reach out to SORBS, explain our position, and get our IP space delisted, we've being told that we must change our reverse DNS naming scheme across our entire network to be considered for delisting. Needless to say, we consider this a ridiculous proposition.
Our primary concern is that mail administrators are using SORBS to blindly drop mail based on the false "dynamic IP" assertion. Although we would consider such a practice to be irresponsible from an administrator's standpoint, this is an issue that's been raised by some of our customers, and we're concerned about the effect it may be having on their ability to deliver legitimate mail. We've always taken an aggressive stance against anything resembling spammy behavior on our network; we're all I.T. veterans, we all despise spam, and we promptly handle any reports of abuse related to our network. It's distressing to see this situation going unresolved. What advice do members of the Slashdot community have on this topic?"
