maybe you should add another ip address of x10hosting edge server 198.91.80.251 to spf txt dns. mine is
"v=spf1 a mx ip4:198.91.81.12 ip4:198.91.80.251 include:_spf.google.com include:mailgun.org -all"
where ip4:198.91.81.12 is where my website host and ip4:198.91.80.251 is the email server of...