Module%209

1
Module 9

• Managing Email Routing

2
Configuring MX Records

• MX records in DNS instruct mail servers where to
  direct email messages

example.com IN MX 10 elm.example.com.example.com
IN MX 20 spruce.example.com.example.com IN MX 3
0 oak.example.com.
domain name class type preference hostname
3
Querying MX Records

• When debugging problems exchanging email with
  other domains, query MX records
• Use nslookup(1)
• Specify set querytypeMX

4
Configuring a Relay Host

• A relay host enables email delivery to be
  centralized
• In main.cf

relay_host oak.example.com or relay_host
192.168.1.17