Thanks Ray.
As a person who has been running large scale email systems for the past
11 years, I can tell you that bandwidth is almost NEVER the problem, nor
is CPU on the mail systems. Mail is all about how fast you can and
can't get data on and off of disk. Disk that has to be completely
redundant, and totally trustworthy, and raid 5+1'd all over the place.
To add a terabyte of disk to our mail system is in the high 6 figures.
You can't just go down to comp-USA and buy a SATA disk and slap some
email on it. It doesn't work. It's been that way for every system I've
run including ones as large as 1 million mail boxes.
As far as greylisting, I can also say that in my 11 years of running
large scale mail systems, greylisting is the single most effective
system I've seen. If we turn off our greylisting system at MSU
tomorrow, we might as well just turn off the entire mail system. We
block over 10 million spams a day with greylisting before they can even
reach our system. That's 50% of the traffic into the system. We get
about 1-2 complaints per week. That's 70 million messages blocked a
week with one complaint. You can work out the percentages on your own.
Of the messages we DO deliver per day, less than 30,000 are deliverd
from "newly" white listed hosts. That means 0.3% of mail delivered in a
day even touches the Greylisting service. Less than one percent of
delivered mail is impacted by this. That's pretty darned good.
Also, we informed every user in the MSU community that we were doing
this. The decision to do this was at a MUCH higher pay grade than
anyone on this list.
So thanks again, Ray, for realizing that not everyone in the world knows
what goes into running a system this large. I really appreciate that
all the support that we've received from the NAG'ers out there.
Thanks,
Matt
Ray Hernandez wrote:
> On Oct 25, 2007, at 9:59 AM, Laurence Bates wrote:
>>
>> All of which seems to me to be a mute point. Why on earth is anyone
>> arguing
>> that email should be slow?
>
> I don't know that I have seen anyone arguing for it to be slow. I see
> them arguing that greylisting is an effective measure against spam. It
> appears that the statistics also support that.
>
>> Ten to fifteen years ago the bandwidths between
>> email sites were such that email was slow of necessity. Today, email
>> is a
>> drop in the bandwidth bucket and rather than expecting delays we
>> should be
>> much more in tune with the common expectation that email is close to
>> immediate.
>
> That is going under the assumption that there is merely a bandwidth
> issue. With the exception of MSU's email group, I don't know that anyone
> on this list is necessarily qualified to remark on how much
> bandwidth/how many cpu cycles/how many blinkenlichten the mail system
> needs at any given time.
>
>> CPU problems in filtering spam I can understand but intentional
>> built-in delays are IMHO incompatible with 21st century organizational
>> practices. This is the NOW generation, not the maybe-sometime crew and
>> email for business, group scheduling and collaboration should be
>> delivered
>> NOW except in cases of exceptional technical constraint or equipment
>> failure. Quite frankly, if I have to wait 30 seconds for some software
>> company to send me a software activation code via email, that's
>> already too
>> long.
>
> What about something like instant messaging? It can be just as secure as
> any email system and it is definitely instant. I have worked for
> organizations before that have used IM quite successfully as a
> means(instantaneously) of collaborating securely over long distances.
>
> --Ray
|
