[81811] in North American Network Operators' Group

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Re: mobile user strawman argument

daemon@ATHENA.MIT.EDU (Brad Knowles)
Thu Jun 30 13:43:00 2005

In-Reply-To: <Pine.LNX.4.21.0506290201180.11993-100000@ruby.he.net>
Date: Thu, 30 Jun 2005 18:43:38 +0200
To: Mike Leber <mleber@he.net>
From: Brad Knowles <brad@stop.mail-abuse.org>
Cc: nanog@merit.edu
Errors-To: owner-nanog@merit.edu


At 2:51 AM -0700 2005-06-29, Mike Leber wrote:

>  Ya, ya, ya... you are going to say 1) its impossible to get people to use
>  designated servers for outgoing email.  Or you will say 2) even if you do
>  this there will still be *spam*! (egads shock horrror!)  Ugh please.

	That's not the problem.  The problem is that there are plenty of 
providers who transparently proxy *all* outgoing SMTP requests to 
their servers, e.g., AOL.  If you publish SPF records for your 
business and a customer is roaming and using AOL to access the 
Internet (which is one of the primary reasons why a lot of people 
keep their AOL accounts), they will be unable to send e-mail as their 
userid on your server, because that connection will instead be 
silently routed to the AOL servers.

	Yes, you can bypass this by using alternative ports, but not all 
MUAs support alternative ports, or support them correctly.

	Of course, if you're going to do this, you should also be doing 
at least SMTPAUTH and preferably TLSSMTP, but then again many clients 
are broken and don't support these technologies or don't support them 
correctly.


	There are alternative solutions to the mobile user problem -- 
webmail services, VPNs, and shell e-mail.  But none of them are a 
panacea, and if you want to talk about a private customer as opposed 
to a business person who is on an official trip, these options are 
much less practical if it is their home ISP who has done this to them.

-- 
Brad Knowles, <brad@stop.mail-abuse.org>

"Those who would give up essential Liberty, to purchase a little
temporary Safety, deserve neither Liberty nor Safety."

     -- Benjamin Franklin (1706-1790), reply of the Pennsylvania
     Assembly to the Governor, November 11, 1755

   SAGE member since 1995.  See <http://www.sage.org/> for more info.

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