Question and response
Question
dig mastercard-email.com. MX
Answer
mastercard-email.com. 3600 MX 10 mxa.mailgun.org.
mastercard-email.com. 3600 MX 10 mastercard-email.com.
mastercard-email.com. 3600 MX 10 reply-mx.s6.exacttarget.com.
mastercard-email.com. 3600 MX 10 mxb.mailgun.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0