salesforce0320192.1b1c3z.custdkim.salesforce.com has no NS records.
NS records for this zone are defined at custdkim.salesforce.com.
NS records for this zone are defined at custdkim.salesforce.com.
Question and response
Question
dig salesforce0320192.1b1c3z.custdkim.salesforce.com. NS
Answer
The response has no answer records.
Authority
custdkim.salesforce.com. 30 SOA mastername.salesforce.com. hostmaster.salesforce.com. 2041226375 1800 900 2592000 1800
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0