Re: [EAI] The value of simplified downgrade

[Shawn Steele <Shawn.Steele at microsoft.com>]

So you aren't suggesting an eai aware client should be able to downgradw w/o an eai aware server on it's side?  That is unnecessarily restrictive.

Sent from my HTC FUZE™, a Windows Mobile® smartphone from AT&T

-----Original Message-----
From: SM <sm at resistor.net>
Sent: Thursday, September 10, 2009 11:12 AM
To: Shawn Steele <Shawn.Steele at microsoft.com>
Cc: ima at ietf.org <ima at ietf.org>
Subject: Re: [EAI] The value of simplified downgrade


Hi Shawn,
At 09:44 10-09-2009, Shawn Steele wrote:
>A problem with a VRFY type solution is that it's a spammers dream,
>since it would tell them good mailboxes.

VRFY could help in getting the EAI-addr.  As that feature has been
turned off in the default configuration since a long time, I'm not
sure whether you can sell it as a solution.  By the way, I can tell
what are the good mailboxes even if VRFY is disabled.

>I'm also concerned that an ask-the-server type solution would be
>more fragile.  Numerous things could make it hard to ask the server,
>yet transmit legacy mail.  For example, would you expect EAI aware
>mail clients to contact the server directly if they don't have an
>EAI aware server?  Port 25 is often blocked, forcing use of a local server.

The EAI mail client (not to be confused with the SMTP client) should
be using the submission port.  You cannot "ask the server" as you'll
run into port 25 blocking and other techniques which prohibits that.

Regards,
-sm