Why is email I send to Gmail is not being received?

When I send an email to a Gmail contact, it does not arrive. I know there are specific domain records for authentication.

I've used cPanel to check email deliverability and it reports that the relevant records, DKIM, SPF and PTR, are correct.

Here are the TXT records.

DKIM:

v=DKIM1; k=rsa; p=MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAoqaJw5FM1RQgIECSaN8T8v7bzvVWi/ydRRTad39MawDQ+SjVLd+EOOJ/d48YGWUoOq8Jh03/vxlh4s5z/Eq/APC/DuPZLZR5IregyrWzWrhCJyiRqe0zc3NKaQg4AOFNkFJovMoIiWgLSPwoAB3EWJhgAe1MLislv8ZdIyuxRMOmCVd9nEkYCRmhJ5J/m13F4h9az6kL9y3kOqdolB7KSY07Sgcx/uGN4WPSIBQXwhlEX6UB1tIVKYzUBkp/hgUUY3PmY+kBW+/YP9gnsnbi8qdNI/X0FJ0ycfaQ+vz655rrJyrMDUqihVhIgw3OlNYNc+4ICUkrZtDxlNEsPs9KHQIDAQAB;

SPF:

v=spf1 a mx include:websitewelcome.com ~all

PTR:

gator4180.hostgator.com.

Is there any other way to check this? Does Gmail, for example, provide a way to check a domain's deliverability? I've been at this for a while and haven't found a way to fix this.