Hello,
I have my own domain, let's say: myrealname.org. I already set up a mail server (mail.myrealname.org) and MX record for that domain, with MX = 10 and it works just fine.
What I need help is with the following. I want to setup a backup mail server with MX = 20, so in case the main mail server is down, the backup mail server will collect the incoming mail. The backup mail server, let's call it myothermachine.org is on another network. How do I set up the backup mail server (using sendmail) to do the following
(1). If mail.myrealname.org is down, collect the incoming mail for that domain, and keep trying to relay the incoming to the mail.myrealname.org.
Put myrealname.org in /etc/mail/relay-domains on the backup mail server.
But the backup mail server should _never_ inform the mail sender that mail.myrealname.org (I've played around with this a bit, and by default the backup mail server sends a respond back to the mail sender saying basically that the main mailserver is down, and it keeps trying to relay. I don't think the sender needs to know that).
Put:
define(`confTO_QUEUEWARN', `10d')dnl
in sendmail.mc on the backup server. The idea is that the queue warning timeout is longer than the queue return ("I've given up trying to deliver this message") timeout, which is 5 days by default.
(2). While doing (1) and keep trying to relay to mail.myrealname.org, I want the backup mail server to also send a copy of all incoming mails to yet another account, say "myname@xxxxxxxxx". So in the case that I am away and cannot bring the main mail server up, I still can get to my emails.
You're on your own there. That's both delivering and queuing mail at the same time. You'll probably need to script it.
> When the
main mail server is back, then the backup mail server should flush all the mails that it stores to the main mail server.
This will happen automatically when the backup server retries delivery, but you can get the main server to "pull" the mail using the etrn.pl script, which you can find easily by googling.
Paul.
