Subject: Research question: How many legitimate mail sources are out there?

From: Matthew Elvey <[email-masked]>
Date: Fri, 12 Aug 2005 21:09:02 -0700

Would someone out there please take a stab at answering this question?  
Or has it been answered already?

What to I mean by a 'mail source'? Well, in technical terms I'm thinking 
someone could say something like:
"Here's info from a large ISP (handling mail for x million customers).
Over a period of ____ it accepted mail from x IP addresses that it 
thinks were sending it mostly ham"

I'd be even happier with something like this:
it accepted mail from x TLD Names in the HELO.

I could live with something like: my greylisting server whitelisted x IP 
addresses (I'm figure John Levine could give us this number quite 
quickly for his a
"several hundred individual mailboxes, a few dozen mailing lists, and 
the abuse.net message forwarding system.")

Of course, sometimes several servers send through one IP, or one server 
sends through several IPs...

I'm guessing that there are under a million such mail sources.  There 
are around .1 billion TLD Names*.

This is apropos this thread: SPF Loses Mindshare at
http://www.circleid.com/article.php?id=1157_0_1_0_C/

*http://www.registrarstats.com/zonefile_enlarged.asp (Could be a few 
times more more, as this doesn't list ccTLDs...)

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From: "Alan DeKok" <[email-masked]>
Date: Sat, 13 Aug 2005 10:40:01 -0400

> Or has it been answered already?

  Yes.  http://www.striker.ottawa.on.ca/~aland/spam/

  The data covers a significant portion of the Internet.

> are around .1 billion TLD Names*.

  Close.  As of a year ago, about 300k IP's.

  Alan DeKok.

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From: Dean Anderson <[email-masked]>
Date: Sat, 13 Aug 2005 20:17:56 -0400 (EDT)

>   Close.  As of a year ago, about 300k IP's.

Really?  300K "legitimate mail sources"?  Worldwide?  "legitimate mail
sources": That would include corporate mail servers, right?  Gee, I think
there are more than that in the United States.  Probably more than that in
Canada, too.   Maybe you want to rethink that a bit.

		--Dean

-- 
Av8 Internet   Prepared to pay a premium for better service?
www.av8.net         faster, more reliable, better service
617 344 9000

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From: John Levine <[email-masked]>
Date: 14 Aug 2005 00:41:02 -0000

>I could live with something like: my greylisting server whitelisted x
>IP addresses (I'm figure John Levine could give us this number quite
>quickly for his a "several hundred individual mailboxes, a few dozen
>mailing lists, and the abuse.net message forwarding system.")

It's about 22,000 addresses.  My fixed greylist covers about 3000 more
addresses in CIDR blocks, of which probably no more than a few hundred
send mail.

I have no idea how this relates to the pattern a larger ISP would see.

R's,
John

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From: "Alan DeKok" <[email-masked]>
Date: Sat, 13 Aug 2005 21:02:57 -0400

Dean Anderson <[email-masked]> wrote:
> Really?

  Yes.

  Sincerely,

  Alan DeKok.