On Tue, 27 Jan 2004, Jim Ray wrote: > Pardon my ignorance. When you set up mx1.* and mx2.*, will each of the two > redundant mail servers chuck the data into a common black box possibly on a > third local area network server such that end users keep on using IMAP or > POP3 without changing any end user settings upon front end server failure?
DNS 101, section 8, "MX Records". Basically you set up an MX record for each incoming mail server in your domain. For most small businesses it is enough to have a primary MX pointing at your real mail server, and a secondary MX pointing at a friend (or TriLUG's server). Note your secondary must be pre-configured to act as your secondary (which is usually pretty simple). Your secondary MX is nothing more than a mail server on some other network, preferably a different ISP than you, that agrees to relay mail on your behalf. MX records have a preference or cost listed next to them. Sender will try to connect to the lowest cost MX first, then the next lowest, and so on. Primary MX is preferably the final destination. Secondary MX will accept mail on behalf of the primary, and then try to relay message to the primary until it comes back online. Usually two MX hosts are enough unless you are AOL or some other relatively enormous mail provider. Even then they usually play tricks by having a load balancer between a single IP and a farm of mail servers. Two MX records may then end up pointing at dozens of servers. But that's another lesson for another time. -- TriLUG mailing list : http://www.trilug.org/mailman/listinfo/trilug TriLUG Organizational FAQ : http://trilug.org/faq/ TriLUG Member Services FAQ : http://members.trilug.org/services_faq/ TriLUG PGP Keyring : http://trilug.org/~chrish/trilug.asc
