mail us  |  mail this page

contact us
training  | 
tech stuff  | 

BIND 9 Support

HOWTO - Configure Mail Servers fail-over

This HOWTO configures a DNS server to provide a 'kinda' fail-over service when the primary mail service is off-line or too busy to accept mail. (MX RR details.)

Define MX records with different priorities e.g.

; zone file fragment
      IN  MX  10 mail.example.com.
      IN  MX  20 mail.example.net.
....
mail  IN  A      192.168.0.4

If the most preferred mail server (mail.example.com) is down or not resonding, mail should be sent to the alternate server (mail.example.net). The server mail.example.net, which in the fragment above is external to the domain and ideally is hosted at a separate geographic location, would typically configured as a simple relay (or forwarder) with a very long retry time (at least 2 - 7 days) in which case it will accept the mail and try and relay it to the proper destination (mail.example.com) over the next 2 - 7 days or whatever you configure the retry time to be.

Beware: There are a number of articles around the web which suggest that many mail systems do a poor job of using the 'preference' value of the MX record.



Problems, comments, suggestions, corrections (including broken links) or something to add? Please take the time from a busy life to 'mail us' (at top of screen), the webmaster (below) or info-support at zytrax. You will have a warm inner glow for the rest of the day.

Pro DNS and BIND by Ron Aitchison

Contents

tech info
guides home
dns articles
intro
contents
1 objectives
big picture
2 concepts
3 reverse map
4 dns types
quickstart
5 install bind
6 samples
reference
7 named.conf
8 zone records
operations
9 howtos
10 tools
11 trouble
programming
12 bind api's
security
13 dns security
bits & bytes
15 messages
resources
notes & tips
registration FAQ
dns resources
dns rfcs
change log

Creative Commons License
This work is licensed under a Creative Commons License.

If you are happy it's OK - but your browser is giving a less than optimal experience on our site. You could, at no charge, upgrade to a W3C STANDARDS COMPLIANT browser such as Firefox

Search

web zytrax.com

Share

Icons made by Icomoon from www.flaticon.com is licensed by CC 3.0 BY
share page via facebook tweet this page

Page

email us Send to a friend feature print this page Display full width page Decrease font size Increase font size

Resources

Systems

FreeBSD
NetBSD
OpenBSD
DragonFlyBSD
Linux.org
Debian Linux

Software

LibreOffice
OpenOffice
Mozilla
GitHub
GNU-Free SW Foundation
get-dns

Organizations

Open Source Initiative
Creative Commons

Misc.

Ibiblio - Library
Open Book Project
Open Directory
Wikipedia

Site

CSS Technology SPF Record Conformant Domain
Copyright © 1994 - 2024 ZyTrax, Inc.
All rights reserved. Legal and Privacy
site by zytrax
hosted by javapipe.com
web-master at zytrax
Page modified: May 16 2022.