Transcript Document 7921325

Module 9
Managing Email Routing
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Configuring MX Records
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MX records in DNS instruct mail servers where
to direct email messages
example.com
example.com
example.com
IN
IN
IN
MX
MX
MX
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elm.example.com.
spruce.example.com.
oak.example.com.
domain name
class
type
preference
hostname
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Querying MX Records
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When debugging problems exchanging email
with other domains, query MX records
Use nslookup(1)
Specify “set querytype=MX”
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Configuring a Relay Host
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A relay host enables email delivery to be
centralized
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In main.cf:
relay_host = oak.example.com
or
relay_host = 192.168.1.17
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