[TriLUG] seeking advice for a bullet-proof mail server

[Ryan Leathers]

My problem there Joseph is that I won't have the luxury of waiting.  In a
nutshell, this mail server is a component of a business process automation
plan.  Some number of the mail messages arriving will be the type that must
be delivered in near real time.  That's why I mentioned using LVS to
distribute incoming mail, or MX balancing. Its not about performance, just
reliability.  If a mail server dies I have to keep chugging even while it is
being recovered.  Queuing will not suffice except for the normal customer
mail.

-----Original Message-----
From: Joseph Tate [mailto:dragonstrider at gmail.com]
Sent: Friday, November 05, 2004 10:19 AM
To: Triangle Linux Users Group discussion list
Subject: Re: [TriLUG] seeking advice for a bullet-proof mail server


On Fri, 5 Nov 2004 09:38:17 -0500, Ryan Leathers
<ryan.leathers at globalknowledge.com> wrote:
> Does anyone have a good suggestion for me to create some redundancy using
> only two hosts?  FYI the hosts themselves are solid hardware with mirrored
> disks.  I also have LVS directors in place so that option is definitely on
> the table in addition to MX record tricks if I can just determine how to
get
> the same data on both hosts.  I'm also open to suggestions other than
qmail
> if there is a good redundancy story specific to some other solution.

The SMTP protocol supplies the necessary redundancy.  A secondary MX
is usually one that is contacted only if the primary MX cannot be for
any reason.  In that case the secondary queues mail and forwards it
when the primary comes back on line.  No need to synchronize content. 
I have this set up for my home operated mail server, and used it at my
last job using a 500 MHz PIII throwaway PC as the secondary MX.  Now,
if you want redundancy on the POP/IMAP end, that's a different story,
but you weren't clear on that, and in fact, in talking about MX
records you are implicitly talking about SMTP.  AFAIK the only
protocol that takes advantage of MX records is SMTP.

-- 
Joseph Tate
Personal e-mail: jtate AT dragonstrider DOT com
Web: http://www.dragonstrider.com
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