On Sat, 13 Feb 1999, Peter van Dijk wrote:
> On Sat, Feb 13, 1999 at 02:35:10PM +0000, Richard Letts wrote:
> > On Sat, 13 Feb 1999, Peter van Dijk wrote:
> >
> > > Err.. this is _very_ common practice, actually. I'm on a fixed-IP
> > > dialup, but I'm my own primary MX nonetheless. Any mailhost failing to
> > > deliver to a secondary MX is Very Broken(tm). Can you name one MTA which
> > > is that stupid?
> >
> > the secondary MX
>
> Err... come again?
the secondary MX should not deliver to itself if it's the best preference
reachable MTA.
> Ok.. let me rephrase my question: do you know one MTA which is so stupid that it will
> not deliver to a secondary MX if the primary MX is down?
no. however the seocndary MX will (unless configured specially)
exponentially backoff delivery attempts to the primary MX. If you're going
to go to
that effort (of specially configuring it) you might as well go the extra
step and set it as the primary MX and configure it to avoid the DNS
altogether. This benefits other sites, since they'll not waste time (and
concurrency remotes) trying to connect to a system which is disconnected
most of the time. the downside is an extra delviery delay whilst mail is
relayed though the secondary MX, but given most dialup nodes (in the Uk
atleast) are disconnected >50% of the time most of the inbound mail will
do this anyway.
Richard
