4 mx (exchanger) – AirLive ES-6000 User Manual

Page 190

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11.4 MX (eXchanger)

It served as a mail agent for DNS server and a window to the outside for mail services. In spite of ailing for

mail server replacement, the mail server could be back to function in no time just by modifying the DNS

address.

Ex.1:

"MX", also known as "Mail eXchanger", is a type of resource record especially designed for mail service.

(Table 11-3, Figure 11-4)

Domain Name

Type

IP Address

host25.airlive.com A

211.22.22.24

mail.airlive.com MX

host25.airlive.com

Table 11-3 Mapping table of Domain name and Mail eXchanger

Figure 11-4 Mapping table of Domain name and Mail eXchanger

Under DOS mode, type nslookup -type=MX

mail.airlive.com

, you will find that mail.airlive.com is mapping

to host25.airlive.com (the mail eXchanger) and its IP address 211. 22. 22. 24.

1.

“nslookup” is the instruction of locating a DNS server.

2. “-type” defines the DNS type.

3. “mail.airlive.com” is the inquired DNS name.

For example, the customer service department of Test company wants to email to [email protected], a

mail server (test.com.tw) served as a SMTP server decides where and how to send the mail by inquiring the

target DNS server.

The MX record of the inquiry of mail.airlive.com is as followed: (Table 11-4)

Domain Name

Type

IP Address

host3.airlive.com A

61.11.11.10

mail.airlive.com MX host3.airlive.com

Table 11-4 MX Record of Querying mail.airlive.com

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