SPF failure despite multiple attempts- Please help

SPF failure despite multiple attempts- Please help

Hi Team,

Despite multiple attempts (after following the steps mentioned in your support forums), I am unable to get my SPF through. My domain is booksthakam.com. I can send and receive emails from both my ids, but I would like to avoid the question mark icon associated with all the emails sent from my account. Mine is a start up and I wish my emails to look professional. This is going on for quite a while. Any help is appreciated. I am also willing to upgrade to a paid version, if that guarantees prompt support and issue resolution. I just need to get this resolved at the earliest.

Thanks 
Nipun