Sending to multiple email servers

[Egil Fujikawa Nes - Webdeal AS]

Last weekend we had a test system with 2 mailgatways 4 mailscanner
servers and around 25 mail servers up. The situation is that I will
close all my mailserver from being public open on port 25. Some of our
customers have mailscanning and some don’t. We have servers on two
different locations and one mailgatway, 2 mailscanners and around 10
mailservers on each location. As backup for the mail that is going to
the first location we have the second location and posit.

We was trying many solutions on the transport from the mailgatway to the
mailscanners, we wanted a failover and load balancing system. One of the
solutions we making a virtual catch-all users that pipe all the mail to
a perl script and send the mail from the perlscript, this was not
working well on heavy load.

We was ending up with a own name server for the two mailgateways where
we used normal MX record on each domain, those domains that was going to
have mailscanning got two MX records, both with 10. So then in normal
use it is going around 50 % of the domains two each of the Mailscanner
servers. On the Mailscanner servers we used transport table from mysql.

This is the only good way that we found to do it, I guess you can
convert this easily two your configuration. Just setup the name server
to hold primary mailserver as 10 and secondary as 15.

Hope our experience can be to help for you, and if you find another way
to do it, please tell me.

Best regards
Egil Fujikawa Nes

WebDeal AS - Teknologiveien 22 - 2815 Gjøvik - NORWAY

Phone: +47 61 13 16 50 - Fax: +47 61 13 16 51
E-mail: post at webdeal.no - URL: www.webdeal.no


-----Original Message-----
From: MailScanner mailing list [mailto:MAILSCANNER at JISCMAIL.AC.UK] On
Behalf Of Howard Yuan
Sent: 3. april 2004 01:52
To: MAILSCANNER at JISCMAIL.AC.UK
Subject: Sending to multiple email servers

Hello all.

I currently have my MailScanner set up to receive mail for anything
going to mydomain.com. Its configured to receive the email, scan it for
viruses and spam, then send it off to my main mailserver, which
distributes the mail to my users. I have three mailservers (in case one
goes down). I was wondering if its possible to set up the MailScanner
to...well, what I'm worried about is if my main mailserver goes down.
Then MailScanner will have no where to send the email. Normally, a
mailserver would scan through the mx records and go to the next server
listed to try to send the email before it sets it aside for retry. I
would like MailScanner to do something equivalent, where it'll try to
send it to one mailserver, if that fails, to try another one, and so on
and so forth before it gives up. Any ideas? Thanx in advance.

Howard