Rob McEwen wrote:
I've got an idea for faster rDNS lookups.
Before I present the solution. Here is the problem...
...basically, rDNS checks are expensive. They sometimes take a few seconds
when done in real time and depend on the timeliness and of other people's
DNS servers. This 1-5 (or more)
Cami asked
Exactly how is this faster than using a dns caching nameserver?
As I mentioned, (1) artificially long caching times (well beyond TTL) can be
set for both negative and positive return and (2) once cached, the lookup is
not dependent on another 3rd party server which might have been
Rob McEwen wrote:
Cami wrote
Exactly how is this faster than using a dns caching nameserver?
As I mentioned, (1) artificially long caching times (well beyond TTL) can be
set for both negative and positive return and (2) once cached, the lookup is
not dependent on another 3rd party server
Rob McEwen wrote:
Please understand, I'm only proposing this as an alternative idea for
checking to see if a sending server's IP address has proper rDNS... NOT any
other type of DNS lookups.
Also, I don't have stats on this, but I know that most mail is spam and I
know that MUCH of this spam
Cami said:
It used to be 80% but Postfix+policyd has reduced it
to barely anything
The fact that you use graylisting as a means of eliminating spam as a 1st line
of defense is makes your 9% of incoming mail is spam as VERY anecdotal for
the purposes of this discussion. Please, don't confuse
...
Rob McEwen wrote:
I've got an idea for faster rDNS lookups.
Before I present the solution. Here is the problem...
...basically, rDNS checks are expensive. They sometimes take a few seconds
when done in real time and depend on the timeliness and of other people's
DNS servers. This 1-5
And for spam domains, IP-jumping is common...
...for well run, legitimate domains, what
you say is indeed correct
Overall, I think you actually make the case FOR my idea of artifically long
cacheing of rDNS checks. And, I think my earlier messages covered the various
scenarios.
the load on the
And for spam domains, IP-jumping is common...
...for well run, legitimate domains, what
you say is indeed correct
Overall, I think you actually make the case FOR my idea of artifically long
cacheing of rDNS checks. And, I think my earlier messages covered the various
scenarios.
the load on the
Rob McEwen wrote:
I've got an idea for faster rDNS lookups.
Before I present the solution. Here is the problem...
...basically, rDNS checks are expensive. They sometimes take a few seconds
when done in real time and depend on the timeliness and of other people's
DNS servers. This 1-5 (or more)
