How to resolve SPF configuration to allow Google sending mails?

Solution 1:

You need to add a SPF DNS record in your DNS server (SPF = Sender Policy Framework). The value of this record is provided in your screenshot already.

It is highly recommended to add not only the SPF record but also a TXT record with the same value. The SPF record will tell receiving Emailservers that the Gmail servers are permitted to send Emails using your domain as sender (details: http://en.wikipedia.org/wiki/Sender_Policy_Framework).

If you have a domain provider who is giving you access to his DNS servers, then there might be a special option to set it up easily for you.