spf.e-dialog.com has no MX records.
Question and response
Question
dig spf.e-dialog.com. MX
Answer
The response has no answer records.
Authority
e-dialog.com. 300 SOA infoblox1.bo3.e-dialog.com. info.e-dialog.com. 2018101374 3600 900 2419200 300
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0