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