So- You have a live Domain of some type.
With live DNS on the Domain.
And hence you cannot have your DNS records returning non valid DNS.
If all you have is an email account on the Domain, not a site?
Then you are never going to be able to use this Domain for Send13, to add DKIM and SPF records that we demand for our security and yours.
As you have to prove you control the Domain by adding them and validating them.
So you either need to host a site on the Domain.
Or host a Click Funnels page on the Domain.
This last option means starting over with Click Funnels and CloudFlare.
But that will cause more problems since you have to move the email MX records there.
Setting up MX records can be hard even for a professional.
And that advice and DNS records comes from you registrar or original host for the site / Domain.
My suggestion is to get a live site on the Domain.
And if you are using Click Funnels, your first stop is Click Funnels support.
To determine if you are going to set up a Click Funnels custom Domain on the Domain in question, or not?
Because it is quite common to come to Send13 support to set up your from address, DKIM and SPF records for Send13.
Then find you need to move it all to CloudFlare later.
Then have to redo everything a second time, to integrate it all with a custom Domain days later.
If this all does not make sense to you, your first stop should be Click Funnels support.
PS If it is a fit, we can work faster on our support chat Facebook page