...
Enter your domain name in the first field (below is that exampledomain.nl), and tick the same values as in the image below. It is important to set up our outgoing e-mail servers at Add any domains that mail deliver this domain: _spf.managedomain.nl.
Note on last option:
We always recommend using a softfail unless the domain is actively abused for spam ( Joe Job ) or when security of the domain plays a very important role. This is because SPF can disrupt email forwarding on the receiving end (something that you can not influence).
...
Set up the SPF record via the Control Panel at (my.codeorange.co.th). After logging in, click on your domain name and choose Name Servers. Add a record now (blue button). Copy the newly created SPF record on openspf.org (at the top of the gray) in the Content field. Note that you only copy the piece between the quotes, so from "v = spf1 up to the quotes at the end, so that it looks like in the picture below.
...