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From: craig@SH.CS.NET (Craig Partridge)
Newsgroups: comp.protocols.tcp-ip
Subject: re: Host-down redirects?
Message-ID: <8809030218.AA20767@ucbvax.Berkeley.EDU>
Date: 1 Sep 88 20:21:23 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
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> The other problem was that some, possibly critical or time-critical
> mail was eventually returned to the sender during that interval.  And,
> as far as I know, there is no "automatic" redirection possible.  Or is
> there?

Frank:

    Automatic redirection is possible using MX RR's in the domain name
system. The feature was included for just this problem.

    Quite simply, you make your backup host a backup mail exchanger (MX).
Then whenever your primary host is down, mail gets delivered to your
backup.  For short term outages, your backup machine simply waits for
your primary to come up again, then forwards the mail on.  But when
the primary is going to be down for a long time, you can reconfigure
your mailer to have the backup actually deliver the mail sitting in
its queues.

Craig