spf-rnmk.reedelsevier.com has no MX records.
Question and response
Question
dig spf-rnmk.reedelsevier.com. MX
Answer
The response has no answer records.
Authority
reedelsevier.com. 900 SOA spn5061.telecom.regn.net. hostmaster.lexisnexis.com. 2801 3600 900 2419200 900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0