On Tue, 2005-05-17 at 08:48, Paul Howarth wrote: > Trouble is, sometimes lack of availability of a mail server is due to > network issues rather than the server itself being down, so "when the > primary is down" may only be true from a limited set of places on the > Net. If you're going to have a backup server, it may as well be up all > the time. But I wouldn't (and don't) have one. > > Paul. A backup email server should be up all the time. As pointed out it needs to be maintained just like the primary. Including synchronizing the various user access lists and things like the greylist database. The last is important since most DNS systems will round robin MX records set to the same values. If the first attempt hits system 1 and greylists the attempt the database needs to be updated on the backup system so if the second attempt hits the backup server the message will get through, otherwise it will be delayed again. In most cases of this type the front end email servers would pass on the email message to a backend system which is what the users connect to for final delivery. In this case I suspect the one server is doing both jobs. -- Scot L. Harris webid@xxxxxxxxxx Never, ever lie to someone you love unless you're absolutely sure they'll never find out the truth.
