Smart Business Lists wrote: > You don't have to make a HOSTS entry on the primary but I think you do > on the secondary. > > I haven't actually tested this to see if it fails if I don't but I > assume the KB article is probably accurate: > http://support.ipswitch.com/kb/IM-19980116-JB14.htm " This way, IMail > will attempt to deliver any mail it receives for that domain to his > machine (bypassing the MX records in DNS, which point to itself and can > create a mail loop)."
RFC 2821 (see 5. Address Resolution and Mail Handling) already details how to avoid mail loops. hosts entries are not needed. > For ETRN purposes the same is true since you are going to need to issue > ETRN <domain> and you want the <domain> translated to a specific IP > which may or may not be the IP returned by DNS. ETRN (RFC 1985) is just a request to speed up retrying queued mail. It doesn't overrule the requirements of RFC 2821. > Say you have MX1 which is primary and Mx2 which is secondary. MX1 is > down or offline so mail now goes to MX2. Now mail destined for MX1 that > is in MX2's Q needs to go to MX1 when MX1 is back on line. On the > secondary server you don't really want the normal DNS checking and > routing to occur though because the only place you ever want mail to go > from the secondary is the primary. Fully covered in RFC 2821, you order the MX records by preference discarding any at your level of preference or higher. > Thus you can use the HOSTS file to > set what is in effect a static route from MX2 to MX1. For ETRN you may > want a specific IP in fact that has nothing to do with normal > translation for the domain. But ETRN something.org is a request to retry sending mail destined to something.org, it doesn't have anything to do with IP addresses. Its possible that you are the tertiary mail server for that domain and the primary is still unreachable but the secondary is now reachable. > At any rate with IMAIL server whenever the > primary comes back up or comes on line and within the Q timer delay the > mail is automatically sent out to the primary as defined in hosts. I > personally think this is an elegant solution. As mentioned above, reaching the primary is not the only possibility when processing the queue. Getting it closer (in MX preference) is the goal. > Sure you can force it to deliver with ETRN but at least you have the > option. MS SMTP server (among others) doesn't do this. You have to > force it to deliver to the primary with an ETRN <domain> command or one > of the (4?) authorization methods with ATRN that MS SMtP server > supports. Don't get me started on Micro$oft products :-) -- [EMAIL PROTECTED] "The avalanche has already started, it is too Rod Dorman late for the pebbles to vote." � Ambassador Kosh Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
