Re: DMARC: perspectives from a listadmin of large open-source lists

Miles Fidelman <> Tue, 15 April 2014 00:46 UTC

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Date: Mon, 14 Apr 2014 20:46:24 -0400
From: Miles Fidelman <>
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Subject: Re: DMARC: perspectives from a listadmin of large open-source lists
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Dave Crocker wrote:
> On 4/14/2014 3:27 PM, Doug Barton wrote:
>> What I AM suggesting however, and I realize that this is a hard pill to
>> swallow for many IETF'ers, is that IN THE GRAND SCHEME OF THINGS mailing
>> list traffic is inconsequential to large e-mail providers.
> That view is popular, but it's quite wrong.
> What /is/ true is that mailing list traffic by users of large mailbox 
> providers, through small, independent mailing list providers, is 
> probably negligible.  That's the category of primary victim of the 
> recent change.

I'm not sure that's true, Dave.

The lists I run, these days, are for things like community 
organizations, parent-teacher groups, churches, and such.  What I find 
is that over half of my subscribers - both in the high-income city where 
I live, and Boston Public Schools (where I used to live) - are coming in 
through yahoo and hotmail accounts, followed by a mix of ISP accounts 
with broadband providers (Comcast, RCN, Verizon in these climes).

Now an awful lot of these folks ALSO have work email, and a lot of some 
other personal email address - so my guess is that:
- folks who don't do a lot of email, sign up for a yahoo or hotmail 
account because it's free and easy
- more sophisticated folks, sign up for a free account to segregate 
truly personal, and work related email from lists, and commercial sites

This also doesn't seem to be limited to more settled folks - all three 
of my college/just-post-college kids have either a hotmail, yahoo, or 
gmail account (1 each) - again, probably because it's free.  They use 
accounts on one of my servers for more official things like job 

Now, given that pretty much every parent with a kid in the local schools 
is on a parent-teacher email list; and everyone in the two churches I 
support is on their respective email lists; and there are very active 
neighborhood level parent and community lists - there are an awful lot 
of email list users around here.  I expect the same is true elsewhere 
(how many people reading this are on a school or church related list, 
not to mention various technical lists?).  And I note that those lists 
are all quite active.

Now, the list activity is still dwarfed by spam - but once you filter 
out the spam, and general commercial crap, I expect what's left in most 
people's email is a mix of directly personal, work, email lists, and 
notifications from social network sites.

I could be wrong on this - but I have a pretty good window into email 
use in this corner of the world, and that's what I see.



In theory, there is no difference between theory and practice.
In practice, there is.   .... Yogi Berra