Question and response
Question
dig smtp02-ia5-sp1.mta.salesforce.com. TXT
Answer
smtp02-ia5-sp1.mta.salesforce.com. 300 TXT "v=spf1 a -all"
Authority
mta.salesforce.com. 7200 NS dns01.salesforce.com.
mta.salesforce.com. 7200 NS dns02.salesforce.com.
mta.salesforce.com. 7200 NS dns03.salesforce.com.
mta.salesforce.com. 7200 NS dns04.salesforce.com.
mta.salesforce.com. 7200 NS dns05.salesforce.com.
mta.salesforce.com. 7200 NS dns06.salesforce.com.
mta.salesforce.com. 7200 NS u2dns1.salesforce.com.
mta.salesforce.com. 7200 NS u2dns2.salesforce.com.
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0