_spf1.telus.com has no MX records.
Question and response
Question
dig _spf1.telus.com. MX
Answer
The response has no answer records.
Authority
telus.com. 3600 SOA dns40.telus.com. dnsadmin2.telus.com. 2019102507 900 7200 3600000 3600
Additional
. 0 OPT ; payload 4096, xrcode 0, version 0, flags 0