(Off-topic for most, but some here should be able to help) I know this is probably a RTFM (RTFRFC?) question, but so far I have only found bits and pieces of the answer and not a composite solution; hopefully someone can summarize for me... We are trying to setup an "alternate" mail host for our primary mail servers so that when one goes down, mail can be delivered to another to avoid mail bounces (undeliverable after xx hours/days) to be queued for the affected host. The obvious method is a prioritized list of MX records for the covered hosts. I tried this once between two hosts and ended up with a forwarding loop so I'm a bit hesitant to experiment by trial and error. The basic question is this: if we have DNS setup like hosta.foo.edu MX 0 hosta.foo.edu MX 10 hostb.foo.edu hostb.foo.edu MX 0 hostb.foo.edu MX 10 hosta.foo.edu It's clear how "the world" sees this and treats these entries, but what about hosta and hostb? If hostb receives mail for hosta, will it follow the MX chain and resend to itself? Is this a default MTA behavior or does it require some tweaking of the MTA? If the latter (and the reason for this message being cross-posted) how is this conveyed to sendmail (Solaris), LSMTP (NT), and/or NetMail (MPE/iX)? Reply directly unless the reply is relevant to the list. Thanks in advance... Jeff Kell <[log in to unmask]>