There is any issue No valid SPF Records 

There is an email spoofing vulnerability.Email spoofing is the forgery of an email header so that the message appears to have originated from someone or somewhere other than the actual source. Email spoofing is a tactic used in phishing and spam campaigns because people are more likely to open an email when they think it has been sent by a legitimate source. The goal of email spoofing is to get recipients to open, and possibly even respond to, a solicitation.

Reference : https://www.digitalocean.com/community/tutorials/how-to-use-an-spf-record-to-prevent-spoofing-improve-e-mail-reliability

Thank you.