At 14:01 2/7/2004, Dale Qualls wrote: >Wouldn't the backup simply give it back to the primary in the exact form = >that it originally received it, hence the smtp relay? The backup is = >actually accepting the message as (what seems to me) the primary would = >then responding that the user doesn't exist even though the backup really = >doesn't know either way (since it doesn't have the users). Shouldn't the = >backup simply "relay" it back to the primary and when the primary sees = >that the user doesn't exist it (the primary) should reply to the original = >sender to tell them that the mailbox doesn't exist? > >I'm thinking that I may not be getting my point across.
What I gather from what you said above is that you want things to go like this: External mail server attempts to deliver mail. Tries primary MX. That machine is unresponsive. Tries secondary MX. Secondary MX accepts mail. Primary MX comes online. Secondary MX delivers mail to primary MX. Primary MX rejects mail due to "no such user". At this point, there are two choices: 1) Primary MX accept the mail on the primary and bounce it to the original envelope sender (which may be - probably is, for spam or viruses - forged, thus sending mail to someone who was not a party to the original transaction) 2) Primary MX rejects the mail in the SMTP protocol session from the secondary MX. This leaves the secondary MX holding the bag. It can either: a) Discard the message b) Freeze the message so that the mail admin can check it over c) Bounce the message back to the original envelope sender (again, possibly, or even probably, forged). How to accomplish each of these varies depending on your configuration. However, what I had posted before provides a different solution. It goes something like: External mail server attempts to deliver mail. Tries primary MX. That machine is unresponsive. Tries secondary MX. Secondary MX rejects (during the protocol session) for "no such user" There are two advantages to this method: 1) Mail sent to invalid users isn't cluttering up space on your secondary MX if your primary is down 2) The mail is rejected during the protocol session, so no uninvolved third parties (ie forged senders) are notified The major disadvantage to the method I posted is that it's high maintenance (having to maintain two copies of the user data). Like I said, I was hoping someone would have a better solution. - To unsubscribe from this list: send the line "unsubscribe xmail" in the body of a message to [EMAIL PROTECTED] For general help: send the line "help" in the body of a message to [EMAIL PROTECTED]
