[82016] in North American Network Operators' Group
Re: OT? /dev/null 5.1.1 email
daemon@ATHENA.MIT.EDU (David Andersen)
Fri Jul 8 15:33:10 2005
In-Reply-To: <20050706032813.4C3723BFF34@berkshire.machshav.com>
Cc: Todd Vierling <tv@duh.org>, Jim Popovitch <jimpop@yahoo.com>,
nanog@nanog.org
From: David Andersen <dga+@cs.cmu.edu>
Date: Tue, 5 Jul 2005 23:37:45 -0400
To: "Steven M. Bellovin" <smb@cs.columbia.edu>
Errors-To: owner-nanog@merit.edu
On Jul 5, 2005, at 11:28 PM, Steven M. Bellovin wrote:
>
> In message <Pine.WNT.4.63.0507052219510.5600@jvc>, Todd Vierling
> writes:
>>
>> The default recommendation I give anyone these days is to use no
>> secondaries, and let the sender's mail server queue it up, as that's
>> the
>> fastest implementation path. As a second stage, and only if the
>> expertise
>> and time is available, then a backup MX with some sort of recipient
>> validation at SMTP time can be implemented.
>>
>
> The usual justification for a secondary MX is when the MX servers have
> some sort of special access to the ultimate recipients -- non-SMTP mail
> delivery, firewalls that they are privileged to pass, etc.
They're also mighty handy when dealing with planned, extended outages,
such as moving to a new {building, ISP, etc.} or, say, losing power to
the {only IX for Moscow, northeastern U.S.}, etc. It's much easier to
configure your backup MXen to not toss messages or send warning emails
after 4h than it is to politely ask all sending SMTP servers to do the
same.
-Dave
