Refer to the exhibit, which shows an nslookup output of MX records of the example.com domain. Which two MTA selection behaviors for the example.com domain are correct? (Choose two.)

Question

Exhibit

Options

• Amx.example.com will receive approximately twice the number of email as mx.hosted.com because
• BThe primary MTA for the example.com domain is mx.hosted.com.
• CThe external MTAs will send email to mx.example.com only if mx.hosted.com is unreachable.
• DThe PriNS server should receive all email for the example.com domain.

• A
  8% (4)
• B
  76% (39)
• D
  16% (8)

Explanation

B is correct because in MX record selection, the server with the lowest priority number is the primary (preferred) MTA - and the exhibit shows mx.hosted.com has a lower priority value than mx.example.com, making it the first destination for incoming mail. C is correct because this is exactly how MX failover works: external MTAs always attempt the lowest-priority MX record first and only fall back to higher-priority (numerically larger) records when the primary is unreachable.

A is wrong because unequal email distribution (2:1 ratio) would only occur if both servers shared the same priority value with different weights - but the exhibit shows different priority numbers, indicating a primary/backup relationship, not load balancing. D is wrong because the PriNS (primary name server) handles DNS queries, not email delivery; MX records specifically designate mail servers, not nameservers.

Memory tip: Think of MX priority like a race - the lowest number crosses the finish line first and wins the mail. Only if that server falls down does the next runner (higher number) take over.

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