Am 11.06.2011 16:55, schrieb Wiebe Cazemier: > That's not what I meant. I meant that 99% of the time, the primary server > will be up and recipient address verification will work to reject (spam) > messages to unknown users. Those two scenario's you mentioned are when > the primary is down or otherwise deferring. And those cases happen 1% of > the time (figure meant to be illustrative).
so you do not need any backup-MX because if your primary is not available the edferring happens on the sender this is teh way smtp works > So if you would accept mail when the primary is down, you may very briefly > create backscatter, but it allows you to operate a backup MX server without > syncing recipient maps, or have any other knowledge about it nut the backup-mx is really useless if it depends on the primary one for proper working and in the reality a backup-mx is useless, really only if you have some database-driven configuration with a replications salve on the backup-mx it makes any sense because your configuration is independent, if you are using a spam-filtering appliance as example the backup-mx is the dead of your spam-filtering and if you are using greylsiting the backup-mx is also the dead of well working service becasue if the primary mx ansers with "temporary problem" the sending server will try your backup-mx and if both of them doing greylist you are playing something like ping-pong with the senders without any sync between the servers
signature.asc
Description: OpenPGP digital signature
