spf.hes.trendmicro.com has no NS records.
NS records for this zone are defined at trendmicro.com.
NS records for this zone are defined at trendmicro.com.
Question and response
Question
dig spf.hes.trendmicro.com. NS
Answer
The response has no answer records.
Authority
trendmicro.com. 300 SOA muc1-tmns3.sdi.trendnet.org. dnsadmin.trendmicro.com. 2007086618 900 300 86400 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0