[82013] in North American Network Operators' Group
Re: OT? /dev/null 5.1.1 email
daemon@ATHENA.MIT.EDU (Steven M. Bellovin)
Fri Jul 8 15:33:04 2005
From: "Steven M. Bellovin" <smb@cs.columbia.edu>
To: Todd Vierling <tv@duh.org>
Cc: Jim Popovitch <jimpop@yahoo.com>, nanog@nanog.org
In-Reply-To: Your message of "Tue, 05 Jul 2005 22:23:13 EDT."
<Pine.WNT.4.63.0507052219510.5600@jvc>
Date: Tue, 05 Jul 2005 23:28:13 -0400
Errors-To: owner-nanog@merit.edu
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.
--Steven M. Bellovin, http://www.cs.columbia.edu/~smb
