4.6 Adding Mail Servers to dnsmasq - BrainDump

Problem

You have some local mail servers that you want your LAN hosts to know about. How do you do this with dnsmasq?

Solution

dnsmasq has a special record type for mailservers. You need these three lines:

  mx-host=alrac.net,mail.alrac.net,5
  mx-target=mail.alrac.net
  localmx

Themx-hostline needs the domain name, server name, and MX priority. Themx-targetline is the server name.localmxmeans all local machines should use this server.

Discussion

A priority number of 5 means the server is higher priority than servers with larger numbers, typically 10 and then multiples of 10. If you have only one mail server, you should still give it a priority to keep clients happy.

See Also

• man 5 dhclient
  
• dnsmasq.conf is also a great help resource
  
• dnsmasq home page (http://www.thekelleys.org.uk/dnsmasq/doc.html) is where you’ll find mailing list archives and excellent help documents
  
• Chapter 24, “Managing Name Resolution,” in Linux Cookbook, by Carla Schroder (O’Reilly)

Please check back for the next part of the series.