spf.emailsignatures365.com has no MX records.
Question and response
Question
dig spf.emailsignatures365.com. MX
Answer
The response has no answer records.
Authority
emailsignatures365.com. 180 SOA ns0.dnsmadeeasy.com. dns.dnsmadeeasy.com. 2008010402 43200 3600 1209600 180
Additional
. 0 OPT ; payload 1280, xrcode 0, version 0, flags 0